iRacing updated their anti cheat program. And looks like it has screwed up Rift users. iRacing is investigating.
See thread on iracing:
We are sorry for the inconvenience.
We believe this to be a known issue that we are looking into and hope to have fixed very soon. There was no update recently with iRacing but there was with the EasyAntiCheat software. We are working with them to resolve this issue.
Thank you for your patience while we are working on this issue