Exchange owa Microsoft.Exchange.Data.Storage.ConnectionFailedTransientException

when i try to connect Wxchangeserver with
owa client
igot
Exception
Exception type: Microsoft.Exchange.Data.Storage.ConnectionFailedTransientException
Exception message: Cannot open mailbox /o=XXX Organization/ou=Exchange Administrative Group (FYDIBOHF23SPDLT)/cn=Recipients/cn=user.name.

this was because
Microsoft Exchange Information Store was stopped

go to services.msc and start the service
for details
click
good luck!