Fixed all in the next build.
While the error message was similar, the count() error was different in this case. Here the count error was thrown because it was encountering a string, while in the other report it was encountering a class instance.
The undefined index tab_style revealed that users who upgraded to Beta 3 were not getting the new tab_style column added to the vw_revision table, which would cause database errors when trying to save page content. Build 002 should automatically detect this situation and correct it.