What EMM version are you on?
Are you having any communication issues with the Proxy to Hub? The error you get is usually when the Proxy cannot get device info from the Hub. Have you tried an IIS reset on the Hub?
Are you getting any errors provisioning devices?
sorry for the few details. The version is 126.96.36.199 and it's a single server setup.
I noticed the error while i was trying to setup the email account manually on Android device. Then I did an iisreset and was able to setup the mail account.