Context menu does not appear when using Firefox 78 ESR with multi process (e10s) disabled on Windows

[plokus]

- On Windows set the user environment variable MOZ_FORCE_DISABLE_E10S=1 (https://techdows.com/2019/08/multi-p...e-is-how.html9)
- Open the showcase application in Firefox ESR 78.0 or later (https://smartclient.com/smartgwt/sho...on_contextmenu)
- right click on the speaker icon

Expected behaviour:
A popup menu opens with the menu elements Visible, Size, Move and Reset.

Actual behaviour:
Nothing happens.

[Isomorphic]

Hi plokus, this is likely a bug you should report to Firefox, perhaps after isolating it more.

If you are stuck and need a solution, you can purchase consulting hours from us and we can see if we can work around the Firefox bug.