Every time I try to open Mp3Tag, I get an annoying error dialog saying "This action cannot be completed because the other program is busy."
Looking at a similar issue here, I have come to believe that this is being caused by update checks. I cannot, however, configure the program to not check for updates. That would be a task for the developer 
I would revert to the previous version of Mp3Tag and simply use that until the issue is resolved, however there is no way to download previous versions. I'm in a bit of pickle here...