Error 0x80070501

Value: -2147023615 | 0x80070501 | 2147943681

What does it mean ?

ERROR_ALREADY_THREAD  
The current thread has already been converted from a fiber.
Value: 1281 | 0x0501 | 0b0000010100000001

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

StackOverflow

Other Errors for FACILITY_WIN32