Hello, sorry to hear you're running into issues. Please contact our support team via the link below, they will look into it for you.
https://support.ubi.com
This is the reason why i've stop to play FH on PC.
After Every major Update i was unable to lunch the game and it always took several days to fix it.
Last time it happen to me, the things the support team wanted me to do due to my problem was so complicated that i just moove back on PS4.
There you dont have to deal with that kind of issues.