Hi all, new to tuning here so forgive my ignorance. I recently tried to tune my 4.8l ls and disable vats/etc in order to complete my ls swap. I am working with a 4.8 psi standalone and 5.3 suburban ECU (P01) but my motor is out of a 4.8 Silverado so i wanted to change the tune file to that of a 4.8 with Vats disabled so that it would work with my motor, and i was under the impression that the only difference between the 5.3 and 4.8 ECU was the tune so i could get away with just changing that. After that i downloaded the necessary stock 4.8 Silverado tune from the tune repository and modified it to remove vats and fit my build, but when i went to write it after navigating the pop ups and spending 2 credits it said that my vehicle was unlicensed. When i visited my license info menu i could clearly see i spent 2 credits on a serial number matching my ecu and when i go to re-license on a new tune file it says i have no credits. Did i waste my credits or what; in the menu it says if you are not using the stock file and modifying it you may need two licenses but i cant seem to find where to even buy the second license. I am very confused as to why i cant write my file after spending the necessary credits, i hope someone can enlighten me.