Hello all, We have been successfully running the "original" DCC++ on our N scale layout using an authentic Arduino Uno and Motor Shield for many years. We recently changed the software to the latest DCC-EX software (3.0.0) and all works well except our programming track. We always get the error "no acknowledgment from locomotive (308)" on every locomotive (we own seven.) Edit -- updated to 3.0.3 with the same results. The locomotives "pulse" while JMRI tries to read CV 8 and CV 7. But we get the above error every time. The wiring is correct. The locos do "pulse." And we get the same error for every locomotive, so it's not the decoder. Programming worked fine with the original DCC++ and we changed nothing other than the software. Any help is greatly appreciated!