I had a rather major issue with the Mac App Store concerning the updates. In the Purchases tab, I could see the apps I had previously downloaded but when I clicked the Update button for each of them, I would get the error message “You have updates available for other accounts…” inviting me to sign in into the “other” account. The problem is that I only have 1 Apple ID and always used this ID.

After contacting the Apple Support, all I got was a totally useless response about re-installing iTunes and that might fix the problem. Even though I knew iTunes had absolutely nothing to do with the Mac App Store, I still followed their instructions and re-installed iTunes. Guess what, it didn’t fix the issue at all. Thanks for your support Apple…not. A few posts in Apple support forums have suggested deleting the apps and re-install them. While it works, it’s not really convenient.

It turns out the issue is related to Spotlight. Apparently, the Mac App Store use the Spotlight index to find which applications are installed on your Mac. So if for some reasons the spotlight index is empty, corrupted or disabled, the Updates tab will always be empty and you’ll get the error message discussed above every single time you try to update your apps. Depending on what makes your spotlight index buggy, there’s various fixes:

Solution 1 – Spotlight works but the index is incomplete or empty:

1) Open System Preferences > Spotlight
2) Under the Privacy tab. Add your Macintosh HD (or whatever your main hard disk is called) to the list.
3) Close the window. Wait a few seconds. Then go back to Spotlight settings and remove the entry you just added.
4) The spotlight index should now begin to re-index completely. (A dot will fade-in/out inside the Spotlight icon in the taskbar)
5) Wait for it to finish and then launch the Mac App Store. You should now see updates in the Updates tab.

Solution 2 – Spotlight indexing is disabled (frequent on Mac OS X Server)

1) Open a Terminal window.
2) Type the following command: sudo mdutil -i on /
3) A message saying “Indexing enabled.” should appear after a few seconds.
4) Close the Terminal window and the Spotlight indexing should now start automatically. (Again, a dot will appear inside the Spotlight icon during the indexing process)
5) Wait for it to finish and then launch the Mac App Store. You should now see updates in the Updates tab.

It would be a good thing for Apple developers to check if the spotlight index is OK before displaying a completely useless error message to the user…