Can't save changes to Stacks

If I add a game to one of my Stacks where the ratings are usually found, it states "undefined." Also, when I try to save changes, the following error message appears: "Title must contain at least one alpha numeric character"

Hopefully this can be fixed, thanks in advance.

This issue still hasn't been resolved completely. I am however, able to add games to a select few of previously created Stacks and move them over to newly created ones. It's a slight annoyance, but it's a workaround for now.