So after reading and learning for the past few weeks I finally decided to write my 03 Denali, and on the first write the timer never started and it didnt write. Then it wouldnt even try to start. I tried with the same file again as support says ( a few times) and get Bootloader time out messages. This really is not a good start for this MPVI2. Ive used the MPVI pro of my buddies before and never had this issue on similar year GM trucks, albeit this was a few years back. Any idea what is causing this, I tried restarting the computer also..and I checked the VCM scanner which has been logging fine and now it wont connect either. I really need this vehicle for a daily driver...yes I know it was a bad idea to flash a vehicle that I "need" to drive but this shouldnt be something we have to worry about. Please someone tell me this has happened to you and its something stupid that I am missing because Im aggravated. Thanks in advance.