Firefox 116.0 is out this week, so next time you try to update, hopefully that will work around the issue.

If you do see the message against, can you make a note of (or screenshot) the specific trojan name?

Thank you, I will wait for 116 as you suggest and if the issue reappears I will do a screen grab and post it below. Your input is much appreciated.

I have tried updating Firefox a number of times to 115.0.3 and each time I have had to roll my PC back to a pre-update state because I get a warning from MS Defender that I have a Trojan. What do I do in order to update the program without this very disconcerting warning? Thanks in advance.

So what what was Defender claiming to be a trojan?

Not the first report of defender claiming something in a new Firefox version of having a trojan. Earlier it was doing false positives in claiming langpacks were trojans

A few examples. /questions/1415443 /questions/1415406 /questions/1415718