Unable to "software update" or download "good" files
 

I suspect a firewall (installed by some PC jamokes) is interfering with our ability to successfully complete -any- Software Update or mount any .dmg (like the Combo Updaters). We've tried Safari and Netscape for the downloads but with the same result.

Has anyone had any similar issues which they would like to share? Perhaps a solution? I suspect something is pooched in the firewall. Of interest is that the PCs don't seem to have this problem (although we've not tried DL'ing Apple software updates using the PCs).

Suggestions appreciated.

Thanks,
Barry

Check to see if your problem might be merely an issue with "/tmp" list those of this old thread:
http://forums.macosxhints.com/showthread.php?t=22763

Tell us in detail what you see - especially what error messages (verbatim) you get.

All five Macs on the network are experiencing this problem. It's not just Software Update; any ".dmg" files or virtually anything downloaded from the Web arrives corrupted. The Macs are running various versions of Panther although one (the oldest, a B&W) is running 9.0. It also has the corruption problem with any downloads. Can't be a software issue unless it's something in the firewall.

Then I ask again for you to show us the error messages - verbatim.

And here's a sample .zip file for you to try uploading - does this also get corrupted?

I am not at the client's location at this moment but I've forwarded them the link to the file. They will let me know what they see. (I was able to DL, unzip, and open the file in TextEdit from my location but I'm not the one having problems!)

I'll post what my client sees ASAP.

Thanks,
Barry

The file was downloaded, unzip'd, and opened without a problem (by my client). Could this be because a zip file has no resource fork to get pooched?

Tried downloading one of the dmg's from Apple's downloads page. Error message was "The following disk images failed to mount" and the name of the image (which was "ProRuntime.dmg") and the Reason (which was "codec overrun").

Hopefully this will provide another clue.

Thanks

I suspect the difference between the successful ZIP and the failed DMG is all about the size of the file - a larger file has more opportunities to get corrupted.

But first, you should check that the DMG file is actually getting corrupted - at the moment all you know is that it fails to mount, which might be due to a failure in the DMG-mounting software.
Download it yourself and look at the size in bytes and then do an MD5 checksum on it.
With the 10.3.9 version of that ProRuntime.dmg file, I get:
Assuming that the file is actually corrupted (different size or checksum) and that this happens repeatably on all of the Macs that your client has, and it happens with a freshly created user on those Macs (to eliminate the possibility that it is some software or configuration that that user has active), then try temporarily turning off that firewall that you suspected and try again (or take one of the Macs and connect it outside of the firewall).

We're going to try one of the Macs outside the firewall. I'm thinking that the PC techies have pooched some setting. Based upon what I've read about stateful packet inspection, I suspect they've got something on port 80 (and whatever port Software Update uses) switched incorrectly. Perhaps the firewall is not passing the resource fork through or maybe it's only passing 7 bits; that would account for the problem yet still yield a file of the same size (zero's filling the now-blank space).

Will rely as soon as we know more. Thanks for the help.

There is usually no resource fork in a DMG file.

Before going to the trouble of moving a Mac outside the firewall, you (or we) might get some clue by looking at the DMG file that did get transferred. (See my suggestions above)

I think taking the Mac to the other end of the firewall is the fastest way to confirm the screwed-up-fw-option.

Once we know it's broken and needs fixing, barrys NOC will have to figure it out.

It might be as simple as a misconfigured transparent proxy.

We moved one of the Macs outside the firewall and even beyond any of the switches (just in case we had something screwy with them). It was the -only- computer connected to the T1 line. The problem was not resolved.

I should point out that these same Macs, when brought to another Internet connection (Roadrunner at one of the employee's homes), have no trouble downloading or running Software Update.

So it seems that something from either SBC or the ISP is fouling things up. We've called the ISP and asked him to get involved.

By the way, the error (when attempting to run Software Update or mount a manually downloaded dmg of that update) occurs during the attempt to mount it and the Mac responds with a suggestion that Repair Permissions be run. Even after that, the error persists. Again, bringing the Mac to another ISP resolves the issue.

It now seems as if you are saying that the problem is only related to Software Update, whereas initially you seemed to be saying that any file downloaded from the Internet was corrupted.
Which is it?
A problem with Software Update may indicate a problem with the network path (proxies etc) between the Mac and Apple.
A general problem with downloaded files (from anywhere) likely indicates something different.

No, the problem exists both with using Software Update -and- downloading those updates manually -and- downloading any other dmg's or img's. The problem exists for both OS9 and OSX Macs -but- the problem disappears when the Mac is taken from that network and connected to another ISP.

In a previous post, I mentioned that an attempt was made to run Software Update from -outside- the firewall and the results were the same: The files downloaded successfully from Apple but, upon the attempt to mount them, SU reported a failure to mount and suggested repairing permissions (which did nothing).

The OS9 Mac downloaded a Toast update (5.something) but, again, the download was reported as corrupted when attempting to mount the image.

We're not running anything bizarre like net-boot. The Mac that was connected outside the firewall was given a proper public IP and configured correctly per the ISP's instructions.

If it works on another ISP's network but not on the T1 from the existing ISP, where would you point the finger? I've got to believe that the Macs are fine but the ISP (either at his location or in the T1 connection - I haven't seen his "box") has something either configured improperly or simply broken.

Suggestions, as always, are appreciated.

Thanks,
Barry

If this is a network problem (including misconfiguration at the ISP, etc), then you would expect it to affect all downloads on all machines - not just on Macs.

You need to stop looking at the symptoms of the problem (e.g. DMG files not mounting) and instead look at the files themselves. The function of the network is to deliver the bits. Does it deliver the bits correctly when a Windows machine is used (with the same ISP that seems to cause the problem)?

Look at the file that is downloaded as I suggested above (file size and checksum - note that MD5 utilities are available for Windows) and see if it is the same file that is downloaded on a Windows machine as on a Mac.
(Of course you need to disable any of the auto-expanding utilities that might change the raw file that was downloaded.)

And when you have this info for a sample download (same file downloaded on a Windows machine and on a Mac), please show it to us and give us sufficient details about where you got the file so we can reproduce the situation on our machines.

Well, it's tough to accept that the network is -not- causing the problem when, on another network, the problem isn't there.

I've since determined that a number of outgoing eMails messages with attachments have been received with corrupted attachments (which were generated within this company's intranet, verified good by being opened by a number of different Macs, and then attached to an eMail using Mail, Entourage, and Communicator (all three delivering eMails with corrupted attachments). The corporate mail server may also be having its own problems although the PC network gurus deny it. (After today, with the firewall -not- being the problem, I can't say they are wrong.) However, eMail sent from their server occasionally takes 5 to 8 hours to be delivered to the recipient. (Yes, that's a different issue; let's address that in another thread at another time.)

PC's using Windows Update have no issues; all work fine.

Certain streaming media can't be played on a Mac within the intranet but plays fine on that same Mac from another ISP. (Sorry, I have no more information than that on this particular topic.)

As for expecting what happens at the ISP to treat both Macs and PCs indentically, I sometimes have my doubts. I do remember those Cisco switches that shipped with spanning tree enabled that brought down the AppleTalk networks in 20 schools here in town until we got that configured properly. Even though this has nothing to do with AppleTalk, I wouldn't be surprised if -something- were mis-configured.

By the way, this problem (with the bad downloads, etc.) has been around this company for over six months; right around the time they contracted with the ISP for the T1 connection.

*sigh*

It looks a lot like the problem is related to the ISP, however, it can be pretty complicated to sort it out because the connection kinda works.
Perhaps hinting your account manager at the ISP that they either get it fixed or you move your business someplace else might give you access to a qualified NOC guy over there to discuss what might go wrong.

Having reproducable proof ready how your downloads get corrupted by comparing MD5-checksums would be a Good Thing.
Try https downloads as well, those can't be proxied without a browser warning so that takes one suspect out of the loop.

Ask them to stop whatever transparent proxying and firewalling they do to your connection and test again.

One additional step: We downloaded the Panther 10.3.9 Combo Updater (.dmg) from Apple website using a PC. We then burned the .dmg to a CD (as a file, of course). We then inserted that CD into one of the Macs (that could not successfully mount that .dmg if it was downloaded on that Mac), double-clicked the .dmg on that PC CD...and the SOB mounted just fine...and the updater would run!

The ISP is sending one if his techies over to troubleshoot this nonsense. We found some extraneous hardware between the T1 plug and the Web Ranger-II router which, I've been told, may have something to do with an attempt by the ISP to enable wireless Internet service (that failed). If it were my call, I'd swap out that router for something else and make sure that nothing "extra" is sitting between the T1 and the router.

I'll post more when we have more to report.

Barry

---bump---

Any results? I am having the exact same problem. I have a satellite internet connection at home, nearly all downloads (and software update) result in the same message. Those same computers attached at work or at my condo works fine - no error. So definitely NOT the computers.

Macs seem to have problems with some internet/network setups, it would be nice to know why.
TIA if anyone can help.:)

What is the message you are referring to?

Why do you think that it is a Mac-related problem as opposed to merely a problem with your Internet connection?
Can you download the same files (from the same servers) successfully on some other machines at the same time as your Macs are having problems?
Are your Macs connected to your satellite feed in the same way as your other machines?

I must apologize for neglecting to post the resolution to our problem (about the Macs receiving corrupted Software Updates or any other DL's from the Web or eMail attachments).

The ISP sent his crew and swapped out his router. That resolved the problem. We never were able to determine exactly what—inside the router—went bad, but the new router (same brand and model but can't remember which) fixed everything.

Yes, all the PC had NO problems; something in the bad router only screwed up attachments/downloads/software-updates for the Macs only.

Thanks for coming back on that, I really do wonder what was wrong with the first router. I'd say 99% of the time there is no networking problems with my Mac, but I have been on three networks where this has happened, and I have no idea what causes it. All my Mac network settings are correct, but I cannot download files/attachments/software update properly. All the PCs on the network have no problem. At one time our network guy actually set one of the local PCs up as a proxy, and I pointed my Mac at that machine. It was slow but worked.

My home case with the satellite is the same as the thread. Downloaded files all have 'codec overrun' when I try to open the DMG file. Software update comes up with a similar problem. I will check small zip files, I haven't really checked that (most files are DMG files, anyway). It is compounded because the local ISP has no clue about Macs, so are not helpful (no offense to them, since this is a really strange problem). I wish someone with good networking experience could help me to debug it. As it is, I just download all files/updates at work, then take my Tibook home and copy over the files. Not a good solution.

Some things to try:
- check that the downloaded DMG (or other file) has the correct size. (Sometimes the size in bytes is listed on the download site, otherwise you might need to download it elsewhere just to check the size)
I suspect that the problems you are having occur when a download is truncated - e.g. when the server disconnects before it is finished.

- try downloading via the 'curl' command-line program.
E.g. (in the Terminal):
curl -o mydownload.dat URL_of_file_to_download
where you would replace "URL_of_file_to_download" with the actual URL (e.g. obtained via copy & paste from Safari)
and where "mydownload.dat" is the name of the file where you want the contents of the download to be stored. (It can be anything you want - usually you would specify this to match the name used in the URL)

sanook

it sounds to me like you HAVE someone with good networking experience trying to help solve your problems. troubleshooting computer problems is pure algebra... you have to eliminate the variables. you should try what he suggested, as it is a *key* variable in this equation. if that doesnt turn anything up... im sure hayne, and anyone else with experience in networking, myself included, will be able to give you a more eduacated attempt at a solution.

i dont mean to come off condecending or negative at all, but haynes got a good idea...

hi five bro

Thanks for the responses, everyone. Much appreciated. Once I get home tonight I'll test curl. Obviously wont work for SU, but if I can get large DMG files to work I'll be happy.

Again, no offense intended at all, I appreciate the help! :o

Bump! "Codec Overrun" and "Invalid Checksum" errors
 

Hi,

This thread is the most similar to the problem I've been having.

Since I started my new job in Jan and have been using a mac for the first time in years I've had problems downloading things.

A few months ago when I finally updated to 10.4.9 I had problems downloading that until I repaired disk permissions and cleaned the cache, when the update came down fine.

Since then everything I've tried to download including all other mac updates - itunes, iphoto, quicktime etc; Firefox, Aquisition, Silverfast and Vuescan (trying to fix another issue with a scanner) all have verification failure upon downloading. When trying to mount I was first getting "invalid checksum" then "codec overrun", and then today invalid checksum again.

the only thing that has come down was the 10.4.10 update which came down first try with no errors.

I've tried several things from several threads I've found.

I've tried resolving disk, permission and cache corruption with Disk Utility and Cocktail.
I've deleted extensions.kextcache, mkext, and com.apple.kernelcaches.
I tried the curl command as stated in this thread, but am not sure if I did it right.

Some suggestions in this thread I don't quite follow...

My ISP is cable and I just tried connecting the ethernet direct to the computer without going through the router and can't get a internet connection. don't know why...

Might this be a router problem?

I'm going to try a download from another mac and see if I can mount a file from disk.

Is there anything else I can do? Should I try a different router?

any help would be much appreciated. Even if I get this file to mount from disk it doens't fix the problem of not being able to download direct to this comp.

thanks in Advance

btw...running 10.4.10 on an iMac6,1 2.33 GHz Intel Core 2 Duo

&uotconchdoggy:

Did you ever find an answer to this? I am experiencing the same issue...every download is corrupted and it just recently started happening. It was running fine at first (downloaded all types of files successfully) but after updating to 10.4.10, I started experiencing this issue...

Anyone else?

- Scott

You should try the standard troubleshooting suggestions:
http://www.apple.com/support/mac101/ (see the "My Mac needs help" section)
http://www.macosxhints.com/article.p...04011205473937
http://forums.osxfaq.com/viewtopic.php?t=7269
http://www.thexlab.com/faqs/faqs.html

In particular, be sure to try logging in as a different user to see if the problem exists there. (Create a new user via the Accounts preference panel if you only have the one user account so far.)

Also be sure to do "Repair Disk" (different from "Repair Disk Permissions"!) in Disk Utility when booted from the Install CD/DVD. I.e. you restart from the Install CD/DVD, then run the version of Disk Utility that is available from one of the menus there.
See this Apple doc:
http://docs.info.apple.com/article.html?artnum=106214

My solution was to swap out the router. I can't begin to list all of the issues I've experienced with routers gone bad. The latest was a periodic lack of Internet access that I was blaming on my cable company; they are an easy target, after all. The problem got so bad that I had even connected both the cable modem and router to a separate power bar so it would be easy for my wife (a non-techie) to know what switch to flip off then on when the problem would occur while I was out of the house. Finally tried resetting the power just on the router and found that that was the culprit. That was the fifth or sixth router I've bought in the last eight years. I've gone through Linksys, Netgear, and Dlink. Dlink products absolutely suck. Netgear routers are mostly okay but I've seen them fail more often than the Linksys routers.

I'm now on DSL and am using the wireless gateway from AT&T; so far it's working well but we'll see if I made a mistake combining both modem and router into one device. At least, during the warranty period, I can point my finger at one vendor if there's an issue. :rolleyes:

Codec Overrun Error
 

Hi,

I have just got broadband, and my iMac G5 Intel (OS 10.4.7) was just fine with the downloads. No Codec Overrun errors at all. I downloaded Google Earth, Skype, all .dmg files and had no problem.

I then did a software update and the problems began!

I did a Firmware update, maybe that is causing the problem, but now I cannot download ANY .dmg files without a Verification failed error and the a Codec Overrun error.

I am reinstalling my whole system - will let you know how this goes.

Does Apple have any comments on this problem???

I FOUND the cause on my Mac!!
 

:D

After re-installing and taking notes of what was happening on my machine, I think I found the problem!!

When I share my Ethernet internet connection via my Airport connection with other machines (in this case my husbands PC), the .dmg downloaded files start giving verification and CODEC OVERRUN errors.

If I go to System Preferences - Sharing - Internet and stop the Internet Sharing, the .dmg downloads come through just fine, verify and open.

This basically means that you cannot share your connection via Airport as it somehow disrupts and corrupts .dmg downloads on your own Mac.

Think Apple should have a look at this problem!!

Hope this helps some of you out!!

Great diagnosis and resolution! Why don't you head over to the Apple Discussions area (Apple.com > Support > Discussions) and post what you've uncovered? Worst case: Someone knows about it already. Best case: You're a heroine. :D

Thanks for posting your solution.

This has been bugging me since 10.4.10 -- although switching internet sharing over airport off makes the problem go away, it gives up a valuable service. I have also make it go away by switching the main internet connection from Ethernet 2 to Ethernet 1. Apple is working on the problem.

Internet sharing was obviously not the problem of the original poster, and it is not my problem, either. I have turned off all firewalls, internet sharing, and file sharing -- still my .dmg files come across corrupted. Here's some more clues to continue the investigation:

Even when I download them to a Windows computer on the network and then transfer the file over ethernet, nope, still corrupt.
And NOW, get this -- when I download it using a PC, put it on a USB flash drive, then transfer it to the Mac that way, still no dice. HOWEVER... it DOES open when I just try to mount it straight from the USB drive, instead of copying and THEN mounting!!! It must have something to do SPECIFICALLY with the writing-to-hard-drive process.

[Edit: Actually, there are multiple causes for the same result here, because Leela's solution obviously worked for her, and switching out the router has worked for the original poster.]

Wow - Expensive and time consuming fixes
 

I am having the same problem. I don't have the money to buy a new router and my PC works fine - so how is it the router? I am not sharing the mac connection with a PC via airport. The one about downloading to a USB device and then it failing when the file is copied to the HD sounds like a promising place to start for Apple. I searched their web site and didn't find this problem listed anywhere. How do we know when they have it fixed? Better yet, how do we download the fix?! I had this problem on OS 10.4. Upgraded to Leopard 10.5 from a CD purchased at Apple store and still have the problem. 1.83 GHz Intel Core Duo, 512 MB, Netgear router.

I am having the same issue as well
 

My ISP is providing us a wirless circuit and a T-1 that both terminate to the same router. The wireless circuit is the primary with the T-1 for failover. when we run on the T-1 I have no issues updating software and downloading .dmg files. When we are on the wireless circuit I do get corrupted .DMG files. My ISP has no macintosh experience so I am having to troubleshoot this issue without much assitance from them.

Does anyone know what is causing this?

After troubleshooting this problem for weeks it was determined that the ethernet plug on the Cisco router was the problem. My ISP came and swapped out the router and everything is fine now.

I had similar problems, after a couple of days of troubleshooting it turned out that the cause was the SPI Firewall on my router (Netgear 614). It seems it was rejecting various packets, and thus corrupting downloads.

So - check if your router has a SPI firewall, and if so, try turning it off before the download.

I was having the same codec overrun problems. I disabled the SPI Firewall on my Netgear router, and the code overrun problems on download went away.

- Don

This problem is making me crazyface.
 

Ok - I'm getting the "codec overrun" problem too - I only see the specific "codec overrun" message on the mac, although the PC is being funky too...

I've got 2 laptops: 1 macbook running OS 10.5.8 and one toshiba PC running vista (blech)

I've reproduced the 'codec overrun' problem while connected to my wireless router (turned off SPI, still an issue) AND while connected directly to the cable modem (scientific Atlanta DPC2100R2) provided by Comcast.

I don't have this problem when I connect to the network at my office across town (also comcast)

The PC is also able to download things just fine on other networks, but on my home network downloads get corrupted and madness ensues.

I'm fairly certain at this point that the problem lies with Comcast, or with my modem. BUT, contact with their support has been spotty - and they have insisted that my connection is just fine. Which it IS, aside from all the problems downloading things...

The problem isn't just with .dmg files either, I'm having various images online fail to load, streaming video won't load anywhere but youtube with any consistency, and I'm getting kinda frustrated...:confused: