WordPress 2.8 has a bug and a rather large one for those who have been unfortunate enough to have experienced it. And it has to do with the automatic (core) upgrade feature. Here’s an excerpt from Dougal Campbell’s recent post about this:
But the big problem driving a quick update is a bug in the core upgrade feature. It seems that in the case where the upgrade can’t be completed for some reason, the upgrade feature was deleting the wrong files when it attempted to clean up. Oops!
Fortunately, this problem can be easily fixed by performing a manual upgrade.
Not everyone has been affected by this problem but if it does rear it’s ugly head it can be frustratingly random in that it often doesn’t give a reason as to why it failed. In other words, when this problem does occur, more often than not it leaves no entry in any of the default WordPress error logs of what might have went wrong. And in that case it’s hard to discern from the usual flurry of upgrade problems due to the few non-compatible plugins that always crop up.
For myself and my two little sites it went rather strangely in that both sites use the same plugins, both were running 2.7.1, both are on the same host/server and both are setup the same way with the exception of themes (the site themes were irrelevant in this case anyway). One site auto-upgraded with no problem whatsoever while the other turned belly up and died—badly. And just for the record, I’ve never had any auto-upgrade fail in the past whether it was built-in or by plugin.
For all that it the problem was easily fixed by an old fashioned FTP re-upgrade so to speak and it’s all running along nicely now. And again, not all users have been affected by this although I’ve not come across any solid reason why this is.
Ah, the beauties of doing it yourself–gotta love it (if you didn’t then you’d never be doing it in the first place). And yet another fine reason for always backing up prior to any upgrade.