Q: ERROR: The product distribution file could not be verified.

This just worked for me!  I was trying to install Mountain Lion.  Did this, and now it works.

can someone help me. i still have the issue. this is my old macbook pro running Lion. haven't used appstore in a while; newly created a new apple id and tring to purchase Mountain Lion get this error. i tried the workaround and deleted the "8z" folder and problem couldn't be resolved yet.

8/3/12 1:11:07.226 AM App Store: FRPurchaseManager: Preflight operation for 537386512 failed with error: Error Domain=com.apple.appstore Code=0 "The product distribution file could not be verified. It may be damaged or was not signed." UserInfo=0x7fbf74c6ffd0 {NSLocalizedFailureReason=Cannot create PKProduct from "file://localhost/var/folders/8z/mtvxx2495jj9n_52_p767fhm0000gn/C/com.apple.app store/537386512/preflight.pfpkg" Error Domain=NSURLErrorDomain Code=-1100 "The requested URL was not found on this server." UserInfo=0x7fbf74bab180 {NSUnderlyingError=0x7fbf74ba7610 "The requested URL was not found on this server.", NSErrorFailingURLStringKey=file:///var/folders/8z/mtvxx2495jj9n_52_p767fhm0000g n/C/com.apple.appstore/537386512/preflight.pfpkg/index.sproduct, NSErrorFailingURLKey=file:///var/folders/8z/mtvxx2495jj9n_52_p767fhm0000gn/C/co m.apple.appstore/537386512/preflight.pfpkg/index.sproduct, NSLocalizedDescription=The requested URL was not found on this server.}, NSLocalizedDescription=The product distribution file could not be verified. It may be damaged or was not signed., NSUnderlyingError=0x7fbf74ba76a0 "The requested URL was not found on this server."}

About a week ago, I had the same problem - I tried every suggested solution but none of them worked and, yes, I tried the one you just mentioned.

However, I found one suggested "fix" for the problem and it was simple: restart your Mac in "Safe Mode"  - press the Shift key as the machine is starting up. Hold it down from the startup chine until you see the words "Safe Boot" in red lettering on the login screen. (NOTE: the preceding italicized words were copied from David Pogue's book"Mac OS X: The Missing Manual.") Opened the App Store and was able to d/l Mountain Lion with no more problems.

It worked for me and I was about at the end of my rope when I tried it.

Good luck!

Safe mode worked!!  Thanks very much!

My folder was called "87".

Back-up + deletion also worked for me. Thanks!

I did something that was very easy

1. Close App Store

2. Launch Finder

3. Press CMD+SHIFT+G

4. Type the following /var/folders

5. copy the folders that are inside /var/folders to another drive and delete them all

6. Launch App Store

7. retry to download your apps

8. You will see that some of the files in /var/folders was recreated.

9. Recopy the ones that are missing

Be happy with your Macs!!!

Hi,

Unfortunately, none of your solutions could help me.

I found the new folder (/var/folder/9r). I deleted this folder as it was mentioned in your post.

But after restarting AppStore the error appears again and the folder as well.

Safe Boot didn't help me as well.

I don't know how to solve this issue ...

Hi Pavel.

You need to close the App Store before you delete the folder.

Delete the folder.

Re-open the App Store and retry to download the App you were trying to. At this moment the download will restart without any problem.

Hope you succeed.

Hi Felipepinac,

Thank you very much for your help!

But, unfortunately, it didn't help me.

The App Store was closed before deleting the folder.

Re-opening the AppStore creates the folder again. As a result, I can't update my iPhoto app... the error apperas again and again.

Same problem. "The product distribution file could not be verified" The fact that I couldn't find any help or support on this topic is unbelievable considering the fact that there are so many people with the same type of problem.

I'm having the same problem deckthehall. Just trying to download Mavericks. Everybody seemed to have this issue with Mountain Lion, but none of the fixes that worked with them works now...

Mine ended up being a block by our network's firewall. My problem is solved.

This wroks;

1. Close App Store

2. Launch Finder

3. Press CMD+SHIFT+G

4. Type the following /var/folders

5. copy the folders that are inside /var/folders to another drive and delete them all

6. Launch App Store

7. retry to download your apps

8. You will see that some of the files in /var/folders was recreated.

9. Recopy the ones that are missing

thnks..it worked wd me..

Thanks, iOS Software Engineer! I had a single app that would not update, and deleting the file in /var/folders, as identified in the Console report, fixed the problem.