Without warning, a mailbox database hosted on an on premise Exchange 2013 Server dismounted and would not mount again. Here is the error message that appeared in the event logs:
Couldn't mount the database that you specified. Specified database: Mailbox Database 0415367950 BizTech Fusion; Error code: An Active Manager operation failed. Error: The database action failed. Error: Operation failed with message: MapiExceptionDatabaseError: Unable to mount database. (hr=0x80004005, ec=1108) Diagnostic context: Lid: 65256 Lid: 10722 StoreEc: 0x454 Lid: 1494 ---- Remote Context Beg ---- Lid: 45120 dwParam: 0xF84705 Lid: 57728 dwParam: 0xF8487C Lid: 46144 dwParam: 0xF84A60 Lid: 34880 dwParam: 0xF84A60 Lid: 34760 StoreEc: 0xFFFFFDFD Lid: 41344 Guid: afd6739b-2e66-41fa-9520-209a182784be Lid: 35200 dwParam: 0x40C Lid: 46144 dwParam: 0xF84F23 Lid: 34880 dwParam: 0xF84F23 Lid: 54472 StoreEc: 0x1388 Lid: 42184 StoreEc: 0x454 Lid: 1750 ---- Remote Context End ---- Lid: 1047 StoreEc: 0x454 [Database: Mailbox Database 0415367950 BizTech Fusion, Server: BTFEX13.hq.biztechfusion.com].
Error: Operation failed with message: MapiExceptionDatabaseError: Unable to mount database. (hr=0x80004005
Error: MapiExceptionNetworkError: Unable to make admin interface connection to server. (hr=0x80040115, ec=-2147221227)
Active Manager failed to mount database Mailbox Database 0415367950 BizTech Fusion on server BTFEX13.hq.biztechfusion.com. Error: An Active Manager operation failed. Error: The database action failed. Error: Operation failed with message: MapiExceptionDatabaseError: Unable to mount database. (hr=0x80004005, ec=1108)
Diagnostic context:
Lid: 65256
Lid: 10722 StoreEc: 0x454
Lid: 1494 ---- Remote Context Beg ----
Lid: 45120 dwParam: 0xF5961
Lid: 57728 dwParam: 0xF5B36
Lid: 46144 dwParam: 0xF5BC3
Lid: 34880 dwParam: 0xF5BC3
Lid: 34760 StoreEc: 0xFFFFFDF0
Lid: 41344 Guid: afd6739b-2e66-41fa-9520-209a182784be
Lid: 35200 dwParam: 0x2FB0
Lid: 46144 dwParam: 0xF619F
Lid: 34880 dwParam: 0xF619F
Lid: 54472 StoreEc: 0x1388
Lid: 42184 StoreEc: 0x454
Lid: 1750 ---- Remote Context End ----
Lid: 1047 StoreEc: 0x454
Resolution: