OBS Stopped shows black for sublime test

[jwgrenning]

I'm on ubuntu 20.04,OBS 27.0.1
I used to be able to use a sublime window as a source. Now the window is transparent (black).

These apps can be a window source
OBS
Firefox
terminal
Chromium


These apps cannot be a source
Chrome
Sublime Text
Ubuntu Software
Rhythm Box

What is wrong?

thanks, james