This is a warning more than a question.
I have a large (0.5MB) Node Red system that has been reliable to date. I have also been backing up the system regularly (about 4 times a day).
But one hour ago, Node Red displayed a dialogue screen to request updating nodes and that there would be no conflictions. I approved the update. After a few minutes of nothing, I realised that I had lost everything.
I did not bother looking into the Pi folders to see what had happened. I simply restored the last backup and accept that I have lost 2 hrs of work.
So my warning is that everyone should backup their flows before allowing Node Red to import updates. I'll look into seeing if I can turn off auto updates...
Perhaps I am missing some bit of knowledge in this area so would welcome any comments. But the purpose of this notes is to warn people to not become complacent with Node Red's reliability and back up often!