I've found a new problem with Wiki, some Wiki pages show up in a specific wiki and others don't after upgrading, but restoring to a new course in Moodle 1.9latest works fine, but restoring this same backup-zip-file to Moodle 2.5 doesn't work at all (see screenshot))
This Wiki is a Trainer-Wiki and has no students inserting anything.
Well, after continuing the restore process, it says that no user data is restored and the Trainer-Wiki is empty again.
And just saving and restoring the Wiki itself as the same effect.
Funny is, that this problem doesn't effect all Trainer-Wikis!
I've read the tracker, and think thi problem will not be fixed soon?! That means I haveto tell all trainer using wikis in past have to look at their courses and rewrite the wikis?
By the way not all Wikis with more than 1 page are empty.