Error 0x80070087

Value: -2147024761 | 0x80070087 | 2147942535

What does it mean ?

ERROR_IS_SUBSTED  
An attempt was made to use a JOIN or SUBST command on a drive that has already been substituted.
Value: 135 | 0x0087 | 0b0000000010000111

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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