Having difficulty with knowledge base, and I need immediate assistance.

I am getting a locked up DraftSight experience when opening an inserted Block attribute. It gave me an error of LineType file not found. The line type is set to "ByBlock". It just freezes. Lost my work when inserting our title block. This never happened with any other version I have used. I have the problem with 2018 SP1 and just loaded SP2, same issue.