getting error when we run the tsm backup every night?

I am getting the VSS error every time I run the Tivoli backup.

the exact error is:

Volume Shadow Copy Service error: Unexpected error calling routine IVssAsync::QueryStatus.  hr = 0x80042318, An error was detected in the Volume Shadow Copy Service (VSS). The problem occurred while trying to contact VSS writers.

please advice in details how to fix this issue since I am not an Exchange expert.

note that the Exchange version is 2010 and running on Windows Server 2008 R2 Enterprise.

Thanks in advance.