Question

Please, explain me what means 1780 RPC_X_NULL_REF_POINTER – “A null reference pointer was passed to the stub.”
There is some code/ where I am calling GetPrinterDriverDirectory():

char DriverDir[MAX_PATH];
LPDWORD needed = 0;
Result = GetPrinterDriverDirectory(NULL, TEXT("Windows x86"), 1, (LPBYTE)&DriverDir, MAX_PATH, needed);

P.S. Spooler and RPC services are running.

Answer 1

The last parameter should be a pointer to a DWORD rather than 0. This should work:

DWORD needed = 0;
Result = GetPrinterDriverDirectory(NULL, TEXT("Windows x86"), 1, (LPBYTE)&DriverDir, MAX_PATH, &needed);