Error Code = 807 System. Internet connectivity was lost

Hi there,
When I opened Tally this morning this Connection Error appeared. I did everything what the error says and nothing works. My Internet connection works just fine and I cannot continue in offline mode. Can anyone help me to skip this error ? What is causing this ?
Thank you !

Connection Error !!
Error Code = 807 System Error Code = 11001
Could not connect to the Tally Server to complete this operation.
Your System/Network administrator will be able to solve this problem.
Reason for Failure:
Internet connectivity was lost.
Tally Server is not reachable.
Possible Solutions:
Check and correct internet connectivity (Or)
Check hosts file entry for Tally Solutions Private. Limited. Server (experts.tallysolutions.com).
What to do now ?
(Select appropriate option and press to continue.)
Retry (after resolving the issues with possible solutions)
Continue in offline mode
