I got longjump error again, chat-history file became locked, couldn't enter chat messages anymore for some reason.
Systemd didn't restart the spectrum-server.

So first attempt to fix it, 'crontab -e' and insert something like this:

# Remove Chat-file every day at 0:00 hour
* 0  * * * rm /opt/PhantomSDR-Plus/v2/chat_history.json

It will remember the chat in memory, but the spectrumserver can write again.