I get this error while entering the license. Your ServiceNow is running at xxx.service-now.com but this license was issued for yyy.service-now.com only.

SnowMirror license is bound to a certain ServiceNow instance host name (e.g. yourcompany.service-now.com). So the ServiceNow host name you configure in Settings -> ServiceNow has to match the license host name. Please do not forget to restart SnowMirror after you change the instance in the Settings. In case of a trial license please feel free to generate yourself another trial license on our website if you need if for a different ServiceNow instance.