Parameter is not valid - unable to save story file
I'm pulling together multiple storyline files into a single file and recieving the error "The project file can not be saved. Parameter is not valid". It seems to only happen when I've added a specific storyline file and unfortunately I'm unable to share the actual story file.
All the story files that I am importing into this one main file are just step by step view mode screencasts with some voice over added. I can't really think of anything that sets this one speciofic file apart from the rest to cause this error.
Anyone have experience with this error message?