Calendar problem on Android - unable to load schedules

Calendar problem on Android - unable to load schedules

We have just migrated to Zoho. 
My calendar on the desktop has my diary. 
I have just downloaded the Zoho calendar app v1.1.1 onto my Android phone. 
I get an error message that says "Unable to load your schedules"
And the options are "retry" - which gives the same error, or "Feedback"