Hi Michael, if the address of the folder containing vsu.exe is added to the Start up box at menu Tools -> Options -> Advanced -> File Locations
then that should o it. However, there are some Visio addons that don't play the game correctly and overwrite other addons menus. The built-in UML and database menus both do this. Even the examples of how to create an addon menu are wrong. The examples show the addon getting the BuiltInUI, modifying it then writing this out to the CustomUI, all addons should check whether the CustomUI exists in the first place.