Thread:Extension talk:CategoryTree/Upgraded to 1.22.6 & category tree not working

I have upgraded my wiki to 1.22.6 and downloaded the latest version of CategoryTree, I get this error:

"3d6d0149] 2014-05-16 13:07:35: Fatal exception of type MWException Notice: Uncommitted DB writes (transaction from DatabaseBase::query (MessageBlobStore::clear)). in /home/wiki_op/website/mediawiki-1.22.6/includes/db/Database.php on line 3944"

Should there be DB updates for this version?

Thanks, Ailsa