QF 6.10.3 on Windows 10: toolbar title has 'null' at the end

[LinuxOnTheDesktop]

Thunderbird 128.8.1esr. Possibly the problem owes (proximately) to my having switched to the rapid-release version of Thunderbird and then switched back to the ESR.

So far as I can see, QF's functionality is unaffected.

[RealRaven2000]

interesting. and reproducible.