I have been unable to find ANY UltraEdit for Mac posts anywhere that relate to moving an UltraEdit window for which the window frame is off-screen.
UltraEdit is VERY prone to do this on my system, but usually closing and re-starting brings the window back on-screen (not convenient at all, but usually works).
It happens whenever I switch to multiple monitors or away from multiple monitors.
Here is a workaround, once the issue happens, that doesn't involve closing the application:
Get any corner that is visible, and expand the size of the window.
Then, on the same corner, hold down [option] while shrinking the window, which keeps the aspect ratio.
Repeat as necessary until the window frame (the part of a Mac OS window with the red, yellow, and green dots) comes into view.
Drag the window to the right screen and re-size as desired.

It is VERY frustrating to see almost no help at all online provided by IDM that doesn't immediately provide Windows-only help and tips in response to any query.
Could we make a Mac OS keyword to avoid Windows-only support?
A separate Wiki?

A question, should the menu for UltraEdit for Mac show a "Window" item? The only thing close I have is "View".

I hope this is helpful to anyone who was unaware of a workaround. Mac OS is my 'second language', so it was not intuitive for me.

You Rock!  This happens to me all the time, especially when changing monitors.

This is one of the most annoying issues with UltraEdit. This issue has been present since they released UE for the Mac. How can we get this issue fixed?

@idm

PLEASE fix this.