Error 0xC00D1B60

Value: -1072882848 | 0xC00D1B60 | 3222084448

What does it mean ?

NS_E_CANNOT_DELETE_ACTIVE_SOURCEGROUP  
It is not possible to remove an active source while encoding.
Value: 7008 | 0x1B60 | 0b0001101101100000

Where does it come from ?

FACILITY_MEDIASERVER  
Windows Media Server
Value: 13 | 0x00D | 0b00001101

Other Errors for FACILITY_MEDIASERVER