When writing e-mails, the space bar on my keyboard stopped responding this morning. It works on other programs. All other keys also work with thunderbird as before. I therefore get no spaces between the words. What is the problem ? How can I fix it in thunderbird ?

Does the same thing happen in safe/troubleshoot mode (under Help menu)?

A friend of mine has got the same problem, using Thunderbird 136 on macOS 12. He has lost spacebar writing spaces, but is able to write spaces into composing email by pressing 'alt-space'. He still hasn't solved the problem. Exchanging profiles didn't help. Reinstalling app (dmg) didn't help. Using his profile on different machine by manual copying did not do different. At this time bug/warped setting seems to be inside macos 12 interacting with thunderbird 136. The macbook pro of his partner does not exibit the "bug", while operating similar software environment, that's remarkable. We are still investigating (before reinstalling this machine!) Any other advise is greatly appreciated. We are listening. March 11,2025: We see the same erratic behaviour of space-bar showing up recently in Textedit app. Checked it is proably in Libreoffice too. That means problem is not Thunderbird, must be rooted in macOS. A post in https://www.macuser.de/threads/problem-mit-macbook-tastatur-leertaste-funktioniert-sporadisch-rote-rahmen-um-felder.905587/ relates this to wrong setting in system setting - accessibility-keyboard. We check this.