In my application I noticed that I could not disable one of the menuitems. Curiously it was the only one that had submenus.
It failed on Windows but it worked on MacOS.
So I decided to file a bug, but I discovered that there exists one since 2011:
[quote]Summary: Can not disable a Submenu
Link: <https://xojo.com/issue/19616>
User “Stephane Pinel” has updated case #19616.
The following comments were left:
»»Status changed from ‘Fixed’ to ‘Fixed & Verified’.
Our testing staff has confirmed that this bug has been fixed.[/quote]
Thanks Xojo.
It seems it was not a Windows issue eventually.