Error 539 - Invalid thread function

Error 539 - Invalid thread function - A valid thread Function may only take one 32-bit LONG INTEGER or DWORD parameter passed BYVAL (by value). This error can occur if the Thread Function does not match the following syntax:

FUNCTION ThreadFuncName (BYVAL param AS {LONG | DWORD}) AS {LONG | DWORD}

Further, the function must use SDECL (StdCall) conventions, it must not be labeled a CALLBACK function, and it must not be an IMPORT.