Frequent "corrupt" download files

Quick update: After having replaced the router as described above, the corrupt download errors are gone, but I'm still getting occasional "broken pipe" when trying to mount an SMB share in the local network. Is this a known issue? Is it related to the Thompson router still being in the network (even behind the router)?

Hey guys, I'm new in this forum, but have been using Macs for ten years.

I recently had the same problem. I tried downloading Adobes latest update to Lightroom, 4.1, and got the same "DMG corrupted" error, plus all other stuff I downloaded, and Apple updates didn't work either.

I reinstalled Lion, but no dice. I tried installing Snow Leopard instead and tried updating that in order to eventually upgrade to Lion, but that didn't work either. All were clean installs with freshly erased HD. I tried resetting my cable router to factory, but still nothing

After working on this for a full 28 hours straight (no sleep), I tried installing Lion again, which still didn't solve anything. I then tried downloading the Lightroom 4.1 on my Win 7 laptop, transferred the dmg to the Mac, and it installed fine! So that told me it wasn't my calble connection.

Then I booted up in safe mode (shift+restart), and behold, I was able to install everything, including updates!

I then did a normal restart, and now I could install stuff and do updates again.

So it turns out that I could have solved this just by booting up in safe mode, and the do a normal restart.

My buddy had the same problem, and this solved it for him in the 2-3 minutes it took to do the two restarts.

I hope someone else can use this as well.

Take care.

I really don't think it's a problem on our end.

For another reason I've recently done a fresh install of OS X but I still, every time, get "corrupted" downloads from Apple.

Downloads from anywhere else are always fine, but always bad from Apple.

I don't think troubleshooting on our end is going to make any difference. It's my opinion that the downloads go bad as they head out of Apple's door.

It really sounds like a faulty network cable, component or connection.

Have you tried conecting one Mac directly to the cable internet provider's Ethernet cable?

(Also, try to borrow a wire from one of the computers that's not having the issue.)

One last recourse, it could be that your provider is capping or otherwise oversubscribing your bandwidth, so you could download "Network Link Conditioner" and set it to lower the maximum capacity of your Macs below about half or two-thirds of what you provider claims you should have access to, and see if things get better.

Definitely try it on one computer at a time while you figure it out as having multiple computers all trying to update software at the same time is just going to confuse your troubleshooting.

Hope this helps!

Well, I may have been celebrating a little too soon, because after my last post I installed iLife '11, and ran Software Update. I had the same problems installing some of the updates as before. Eventually I could install the iLife updates one at a time, but iPhoto 9.2.3 update simply couldn't install, neither would the standalone installer.

This morning I changed the T-cable connector that connects the cable to my cable-router, and now the iPhoto update installed without problems. I'm not sure if that was just a coincidense...

However (I also have Adobe Master Collection CS5.5 installed), running Adobe Update Utility installed updates for all my CS5.5 applications, but not for Flash Builder. I tried downloading the standalone installer, but got the message about "Image Corrupt".

Other stuff I have tried, is to download the new Adobe CS6 collection, first trying direct links using both Safari and Firefox, and using the Adobe Download Assistant, and all methods produced corrupt DMG's.

This was on my home 50Mbit cable connection. I will bring my iMac to my office, and try the office 100Mbit fiber connection later today. That should clear it up.

I don't know about your specific setup (ISP, Modem, Router, etc...)

I've seen many claims about this issue

Some blame the network cable, some the computer RAM/Disk, some pretend it's Apple fault.

I initially thought it was browser related, since I was able to download 3 consecutive times a non-corrupted file using Chrome, and had 0% success with Safari.

100% of Cablecom customers who have changed their Thomson TWG870UG (or disabled routing) don't have the issue any more. If you have that cable modem, try that first and don't bother looking deeper. Disable routing and/or exchange it.

If you're not, here is a suggestion for troubleshooting:

Try downloading an iOS update using the direct link (http://osxdaily.com/2012/03/07/ios-5-1-download/).

But don't do it once. Do it 5, 10 times. Then run md5sum on them from a terminal.

If you only have one checksum, you're likely not to have any download corruption issue (or you're very lucky).

If you have a vast majority of one checksum: a/ you can reproduce b/ you're very likely to have found the 'right' file, so you might try using it for upgrading your iPhone/iPad

Once you can reproduce the issue (and that you know which MD5 is the right one), try either another Mac from same location, or same Mac using another connection (wired vs wifi, then from office/friends). But only change one thing at the time. Once you can't reproduce the issue with 10, 20 downloads, you found the root cause.

That should tell you if you're issue is from you Modem/Router, local network (bad cable or crappy wifi), or RAM.

Allright, I brought my iMac to my office, pligter it into our 100Mbit fiber connection, and everything worked!

So I'm really glad that it wasn't my harddrive failing.

I called my ISP, and asked for an open configuration of the Netgear CG3000 router they sent me, which would allow me to disable NAT and put it in bridge mode, then using a Dlink N router I had lying around instead.

So far, that setup works at home. For the record, my ISP is YouSee Denmark... They even said that I wasn't the first guy calling them about this particular problem.

Thanks a lot for pointing me in the right direction. I was going crazy over this!

I too experienced the same problems with Apple related downloads. Downloads from other sources worked fine, and downloads while on a network other than my home worked fine.

I've got TimeWarner wideband service in Austin, TX. I took the Motorola modem and disabled the router feature making it act like a bridge. Then configured my airport extereme to act like a router. This solved the problem for me.

You just made my brow furrow Astrojams. For a long time I've had the same providor in Southern California, same hardware and have set it up the same as you.

... and still deal with the same problem.

Wayne, I had to look up "brow furrow" to understand what emotion you were trying to convey. 🙂

So this is what I tried that helped me narrow down the problem.

Note: Test downloads were XCode (1+ gig download) from the Apple Developer site and a 1+ Gig movie from iTunes. Both would fail with different errors. Xcode would be a corrupted DMG and iTunes would throw up error 50.

1. Took my notebook to an Apple Store and tried downloading from Apple via their wifi. It worked successfully, no corrupted downloads, so I assume my notebook or the software on it is not causing the problem.

2. I connected my notebook directly to my broadband modem (in this case it was a Motorola Wideband device) and I was able to get it to fail. (Downloads were corrupted.)

3. I put the modem into bridge mode with my notebook connected directly to the modem and I was not able to get it to fail. Also, I noticed that my download speeds were consistently higher.

4. I setup my Airport extreme to be a router with DHCP server. Downloads continue to work fine and I'm also getting the consistent higher speeds. The Airport is connected directly to the modem using the same cable that I tested my notebook with in the previous step. (This rules out a problem with the cable.)

My wideband service with Time Warner in Austin gets me 6.3MB/sec downloads. Before configuring the modem to act like a bridge I was seeing bursts of 6MB/sec and the connection would fluctuate between 6MB - 2MB. It was really inconsistent.

I made the configuration change last night, so it probably hasn't been enough time to fully vet it. Also, in the process of configuring everything, I had the modem reset and the Airport Extreme powered off. There could be a situation where after a period of time, the modem fills up some sort of buffer and gets out of wack and the problem doesn't appear until then.

My modem is a Motorola SBG6850. My Airport is the latest version of the Extreme.

I've tested several Macbooks, iPads and iPhones on it. I'm also using a Nest and Apple TV which are both connected wirelessly. Everything seems fine.

Hope this helps.

FWIW, I consistently get good downloads via RoadRunner cable (boosted to 20 Mbps) with the Surfboard SB6580 modem and an ancient D-Link EBR2310 router. However, I only use them wired, no wireless here.

Astrojams,

Could you possibly give the exact settings you used to configure your Motorola modem & your AirPort Extreme?

I have the same issue using the same service with same Motorola equipment.

Thanks for any help!

That is when my issue started as well. And I was really only getting about 25Mbps wirelessly with the Motorola.

I ended up putting it in bridge mode and getting an Airport Extreme Base Station. I have not had any issues whatsoever since doing that and even get 50Mbps now.