I often use the File → Export Dashboard action in the Dashboard Designer. Then I would tinker around, and sometimes just quickly revert to the .dbd that I’ve exported.
Well to be able to re-import the .dbd you must delete the existing one, it wont just overwrite it (I think it used to).
When you delete it… it also removes the Menu Entry for that Dashboard.
Sometimes you are working on the Dashboard, it should not delete the Menu.
On the other hand, I find it useful that it does this, since I don’t have to go into menu maintenance to delete the entry. Maybe there should be a checkbox to preserve it or something?
Alternatively, allow overwrite of dashboard with a checkbox. Deleting the menu item makes sense to me, but allowing to re-import fixes the original issue.