By Graham K. Rogers

Not everyone was able to take advantage of the shift in Apple's charging policies when the latest version of OS X, 10.9 Mavericks, was released. I updated immediately as I always do. Many hang back, expecting the new release to have problems. They are waiting for the 10.9.1 release, which may be ready soon. Some others were ready to make the leap, but were held back for other reasons.

A colleague in my office has a fairly long history of Mac use. When she returned from the USA, she had one of the old polycarbonate MacBooks, which she later changed to a Mac mini for her office, using the Faculty-provided Acer monitor and Microsoft mouse, with a generic keyboard.

When Mavericks was released, she asked me a couple of times about it and had a look at my own MacBook Pro computers (the older 15" version and its 13" replacement). She was certainly interested in updating to the latest OS X version, but was still running the 10.6 version of Snow Leopard. With that, there was no access to the App Store which was first included with 10.6.8.

After some persuasion, she downloaded the update and seemed all set. However, each time that the App Store application was started, it crashed. I made a couple of suggestions, the first being that she download the 10.6.8 Combo update and install that over the current. That is actually easier said than done as the network connections where we are sometimes slow to a crawl. This was one of those times.

After a number of tries, the Combo update was installed, but there was no difference with the behaviour: Start App Store, crash. I suggested resorting to the tried and tested method of trashing the preferences file. The property list file (.PLIST) is found in the user's Preferences folder with the name com.apple.appstore.plist.

That folder is in the Library folder which may not be visible if a user clicks on the Home folder for a User account. In that case, use the Finder "Go" menu and the item "Go to Folder" (or the key combination Shift + Command + G). In the panel that opens I type in the word, "Library": the folder then appears - partly greyed out - and the Preferences panel is in there. I did this for my colleague, but when the PLIST file was deleted, the App Store app still crashed.

I tried another tack and asked my colleague to switch to the Admin account. Like me, she rarely uses this, preferring to work in an account with basic user-level permissions.

This time, the application did not crash and she was able to use the App Store as normal. She began the download of Mavericks although again the connections caused several delays. Eventually, however, the complete file was downloaded and the installation process was completed not long after.

When we were sure that Mavericks was working, she tried the App Store app: first in the Admin account, then in the User account. It was working properly and there were no crashes. I suspect that somewhere in her User account installation was a corrupted file and that this was over-written when the new version of OS X was installed.

I did of course have a Plan C.

Graham K. Rogers teaches at the Faculty of Engineering, Mahidol University in Thailand where he is also Assistant Dean. He wrote in the Bangkok Post, Database supplement on IT subjects. For the last seven years of Database he wrote a column on Apple and Macs.