The DAG was setup some time ago, and I just started getting this error
Server01 FileShareQuorum *FAILED* File share witness resource 'File Share Witness doesn't have a file share configured. File share witness arbitration can't be performed until the file share witness share has been properly configured.
Server01 QuorumGroup *FAILED* Quorum resource 'Cluster Group' is not online on server 'Server1'. Database availability group 'DAG01' might not be reachable or may have lost redundancy. Error:
File Share Witness : Offline
is offline. Please verify that the Cluster service is running on the server.