Hi! Usually when we move from xx.wiki to Commons any wiki links will be changed from [[foo]] to [[:xx:foo]] but today I noticed one link was not changed. I fixed it manually but I wonder why that one link was not changed.
Topic on Help talk:Extension:FileImporter
As it turns out this is indeed a bug. I created phab:T258929 as well as a fix. Thanks a lot for the report! This is very helpful.
It is me that say thank you! FileImporter is really a great tool! I tell everyone to use that when copying files to Commons!