Users reporting us, that they are missing files, after they automatically updated to WordPress version 2.8 and there were a problem while updating. We checked out the WordPress Trac and found a brand new record, which confirms this: Trac ticket # 10140
What happened and what are the conditions?
On one hand, the upgrade process has to be so far that the files were downloaded and unpacked. If anything goes wrong after these steps (wrong write permissions, etc.), the upgrade process makes a rollback and usually clears the downloaded files without any problems.
So much for theory. The practice shows, however, in exactly this case, because of a bug, previous existing installation files accidentally get deleted too, so the blog will no longer work!
