My NAV screen is blank and flashes 50/51 on the climate control portion. I went in to the diagnostic menu and by mistake set it to upgrade the software. Now that I know that the software is not on the Map DVD I'm stuck. I tried disconnecting the battery for 20 minutes. I read in the X-Type forum that I can put a file on a Dual-Layer DVD and it should read it and come back to life. Is this file the loading.kwi or is it another file? I tried the loading.kwi and nothing.