Your system has run out of application memory
On a MacBook Air with MacOS Monterey 12.1, I use Firefox 96.0.2 and Thunderbird 91.5.0. I bought this MacBook in October 2021, with 16 GB of unified RAM and 1 TB of main memory, of which 380 GB are available. Annoyingly, I get the message "Your system has run out of application memory." regularly, seriously interrupting my work, because I have to force quit Firefox and/or Thunderbird. This even happens about a day after restart.
In a typical instance, memory usage is: DeepL 67.7 MB Firefox 2.03 GB Preview 334.1 MB Thunderbird 907.4 MB Finder 75.0 MB
The answers I see on Mozilla Support do not solve my problem. In ~/Library/Application\ Support/Firefox/Profiles/aurrzm6j.default and in ~/Library/Caches/Firefox/Profiles/aurrzm6j.default, I see nothing whose name relates to Firefox.
After many and long telephone sessions with Apple Support, they conclude that my hardware, in particular the RAM module, is perfectly fine and the problem lies with lacking adaptation of the Mozilla software to the system I use.
My questions to Mozilla: Is this a known problem? Does it occur with other users as well? What is Mozilla's stand on Apple's assessment?
Sincerely, Joachim von zur Gathen