R6400v2. Had to reboot the router. My thermostat will not reconnect - get a provisioning error?

What this thermostat?

 

What gives error?

 

Apologies for all the questions. But you can help people to help you by providing the information suggested in this forum's header:

 

Subject (Include model number and brief summary)
Model (Recommended - Helps the community give the best answers)
Body (Include additional detail including model version, firmware, OS and environment where relevant.)

They are there for a good reason.

 

PS Please don't use the subject to cram in the query.