The cause of that error is a movie thread that doesn't contain the proper BB Codes in the first post for a movie thread.
Usually it's a movie thread that's been edited in XF1 and not properly formatted.
The only way to figure out which thread is causing it and why it's happening is to get a copy of your database and throw it on a development server to run the conversion there.
Usually it's a movie thread that's been edited in XF1 and not properly formatted.
The only way to figure out which thread is causing it and why it's happening is to get a copy of your database and throw it on a development server to run the conversion there.