Hi Alistair, On 09/22/17 11:50, Alistair Leslie-Hughes wrote: > +int CDECL MSVCRT_clearerr_s(MSVCRT_FILE* file) > +{ > + TRACE(":file (%p) fd (%d)\n",file,file->_file); > + > + if (!MSVCRT_CHECK_PMT(file != NULL)) return MSVCRT_EINVAL; You're checking if file != NULL after using it in TRACE message. Thanks, Piotr