Windows 7 all machines. Adobe apps all updated. CC updated. etc. This has been an issue for some time. We just finally were able to narrow it down to the cause and sequence.
So with designer panel open, this one responsive web page open (that has CSS calling media query), and then press f10 to see code view. Then close the web page (CRTL-W).
When your web page is (the only page) open, make sure it is in DESIGN VIEW (not live or code), make sure CSS Designer panel is fully open not just bump out, and then open CODE view (separate window), then CLOSE the web page.
This is all local machines. No network drives. No cloud.
IMPORTANT NOTE: Something we just found out and tested on multiple machines. It DOES NOT crash if the Global (which is showing the @media Global) is not open. For example, you can have CSS Designer panel open and yet the Global sub panel is not open. If you open that, then do the scenario above, it will crash.
So this could even further make it harder to track and also many users may not see it right away. Because that panel is not always open. We happen to have all those CSS designer panels open, so it crashed every time. But now we see, if we open any of those panels, Source, Selectors, etc. it is fine. As long as the Global panel is NOT open. Once you open that panel (you see the media query), then you can make it crash with the steps above in my first note.
So maybe Jon you can please try and make sure your Global panel is open and in view. Thanks
