You recieve alerts or see in your event logs the following Warnings and Errors:
[2012/08/01 23:41:45.568] (2) Warning :<WatchDog> (36748) Storage integrity fatal error encountered. Description: (cannot start a transaction within a transaction).
[2012/08/01 23:41:45.599] (2) Warning :<WatchDog> (36709) Service is about to be automatically restarted.
[2012/08/01 23:41:45.708] (2) Error :<WatchDog> (36710) Cannot initiate service restart. Code : 0x800b0100,Description : No signature was present in the subject.
[2012/08/01 23:41:45.755] (3) Error :<Calendar Receiver>
(43622) Packet Queue processing failed. Code : 0x80049f0e,Description : unable to open database file[EIP: 0x049C7A82,0x049C7C14][EIP: 0x06E830FC,0x07E70BCB]
Having UAC and an AntiVirus program running may be the cause of this problem. The warnings and errors can happen if the Collaboration Services Database files are locked. The locks can be caused by the indexing service, AntiVirus scanners, or any other software which interacts directly with the file system at the time of the error and warning.
WORKAROUND
Restarting the Collaboration Services server has been known to temporarily correct the problem but the issue may arise again.
Temporarily Disable AntiVirus software on the Collaboration Services workstation and investigate any indexing that may be going on at the time of the Watchdog errors and warnings. This will help you narrow down the exact cause.
