Do you happen to have the Fanatec Wheelbase 2.5? The reason I ask is that I have the Fanatec WB 2.5 and as soon as I started to play ACC, I lost my FFB. Then I reinstalled Fanatec a dozen times, completely rebuilt my Win 10 64 PC about 5 times because my WB2.5 was not working anymore. I had to completely reset everything. Then as I started putting AC, RR and PC2 back on I noticed everything was fine until I installed and went back into ACC. I was already communicating with Fanatec ready to send my WB 2.5 to Fanatec for repair it was so bad. But right now, I believe there is something up with ACC that hoses the Wheel base. I haven't totally confirmed this yet. But at this time I only have AC, RR, and PC2 installed without ACC and everything seems to be fine.