Crashing on User Interface customisation

Hi, I'm having trouble with customising the ribbon.

Every time I do it (which I've done multiple times before on previous versions) I go to save it and, as soon as I hit Apply, the program crashes and it generates a crash report.

I'm currently on a Free Trial as I'm moving to a new computer and wanted to get it up and running before I migrate my account across. Is this part of the problem?

Any ideas would be greatly appreciated. I can't use this program if it won't work on the new computer, and I have 2 weeks to get it working before the subscription rolls over. I won't need it if it doesn't work and will have to look for alternative programs.

Thanks