Hi, Guillermo,
I’m having the same problem using Encore CS5 with Mac High Sierra OS 10.13.4. This is driving me bonkers. Every time I try to add a new menu, whether with File > New > Menu, command-M, double-clicking one from the library, etc., it crashes the program. I’ve also tried trashing the preferences and even restarting the machine.
Did you ever find a solution?
Thanks,
Karen