Error 0x80070021

Value: -2147024863 | 0x80070021 | 2147942433

What does it mean ?

ERROR_LOCK_VIOLATION  
The process cannot access the file because another process has locked a portion of the file.
Value: 33 | 0x0021 | 0b0000000000100001

Where does it come from ?

FACILITY_WIN32  
Provides a way to handle error codes from functions in the Win32 API as an HRESULT. (Error codes in 16 - bit OLE that duplicated Win32 error codes have also been changed to FACILITY_WIN32)
Value: 7 | 0x007 | 0b00000111

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