I also run Norton. is the latest. I just updated to it. During the uninstall process, I got an error, and found the previous version was running still. It didnt terminate properly. After fixing that, it installed and runs ok.
There's been a bunch of issues with False Positives lately - had that happen with a ZWO ASI driver update a day or two ago.
I've reported that one.
Not sure about FMAX though.
Maybe try doing a LiveUpdate on your Norton.