Error 0x00040100

Value: 262400 | 0x00040100 | 262400

What does it mean ?

DRAGDROP_S_DROP  
Successful drop took place
Value: 256 | 0x0100 | 0b0000000100000000

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

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Other Errors for FACILITY_ITF