This article applies to Windows only.
In the meantime, in Firefox versions previous to 76, you can set the number of Firefox processes to "1" to resolve the issue:
Setting the number of processes to 1 effectively turns off the multiprocess feature, which may significantly affect Firefox's performance.
- Click on the menu button to open the menu panel.
- Click the menu button and select . .
- In the General panel, scroll down to Performance.
- Remove the check mark next to Use recommended performance settings.
- Choose 1 in the drop-down menu for Content process limit.