Error 0x80042409

Value: -2147212279 | 0x80042409 | 2147755017

What does it mean ?

VDS_E_OPERATION_PENDING  
The operation has not been completed yet.
Value: 9225 | 0x2409 | 0b0010010000001001
VSS_E_WRITER_STATUS_NOT_AVAILABLE  
Writer status is not available for one or more writers. A writer may have reached the limit to the number of available backup-restore session states.
Value: 9225 | 0x2409 | 0b0010010000001001

Where does it come from ?

FACILITY_ITF  
COM/OLE Interface management. FACILITY_ITF is designated for user-defined error codes returned from interface methods
Value: 4 | 0x004 | 0b00000100

Other Errors for FACILITY_ITF