Thread:Project:Support desk/How to fix pages with invalid titles?

Issue: A change in namespaces after installing Extension:SematicForms caused the namespaces Form: and Property: to temporarilly disappear. Now the pages (formerly) in those namespaces seem to have lost their namespace and their pagenames start with a colon ":" which makes them pages with invalid pagenames. The single revisions of those pages are still accessible in their history but trying to edit or move those pages redirects you to a pagename without the colon ":", meaning to pagenames of pages that do not exist.

Question: Is there a way to fix this?

Example page: Formerly in namespace Form: http://www.entropiaplanets.com/w/index.php?title=:Planet_Info_Overview&oldid=22846

Versions:
 * MW 1.17.0
 * PHP 5.3.3
 * MySQL 5.0.77
 * SMW 1.6
 * SF 2.2.1