If you bench GTX-980 on Ln2 for FireStrike you have probably gotten this error, which will force you to totally restart your PC before the bench will run again.
Tried to find some ways that you can fix it without having to reboot and mess with CBB's on GPU and CPU and save time.
Didnt work list:
Log out / Log back in
Crash GPU driver on purpose
Close and Reopen bench
Set GPU clocks default then back again
What works is just start skydiver till it runs 1 second then escape out, now you can run FS without the error and without rebooting
Hope this can help some people save some money and time.