I took a Laptop that never had HP Tuners. Windows 10, fully patched. Loaded 4.8.7. Loaded Drivers from their Web Site. I did NOT download the Beta. I read the car successfully and saved the tune. I made two small changes and selected write to the vehicle. It prompted me to apply the 2 Credits, which I did. I did not apply one to the Fuel Control Module. (2010 Camaro SS Auto) The Application of credits appeared to be successful. I resynced the interface. I then tried to write the changes and it said that I did not have enough credits. I exited the program and deleted Licence.dat as many Forums have suggested. I repeated the process several times and was unable to write to the vehicle. I tried today on a different laptop. It also had 4.8.7. I read the tune successfully, Sync'd the Interface and it said the sync was successful. It also said that I did not have enough credits. I also again deleted the License.dat on that laptop. I have not plugged this interface into any other vehicle than the one I am trying to write to. All of the times I did the Sync on the Interface, I had Internet Connectivity and it said each time on both laptops that it was successful. I never have trouble reading the vehicle and saving the original tune. This was recently purchased and this is the only vehicle it touched. I read and saved what was on the car. I contacted HP Tuners Tech Support and they have asked twice for files, which I have given. Anyone?