Error 0x80040100

Value: -2147221248 | 0x80040100 | 2147746048

What does it mean ?

DRAGDROP_E_NOTREGISTERED  
Trying to revoke a drop target that has not been registered
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

StackOverflow

Other Errors for FACILITY_ITF