Solution
To restore polling:
Open Clinic Maintenance in RIO.
Check that a stream is set up for the relevant session and clinic.
If no stream is present, create one and retry polling.
Cause
This issue can occur when a required stream has not been set up for the session and clinic in RIO.
Once the correct stream is in place, polling should resume as expected.
Related error message
This issue relates to the message documented in Doc5 under:
Why can't I poll at the moment?