I recently added some functionality through the configurator, fan controlled by temperature, lights, BLTouch (Z-Probe) and others thing.
From that moment Repetier stopped working on my RAMPS, while "MarlinKimbra" (Marlin) works perfectly.
I also tried with the small LCD and does exactly the same thing.
I know that Arduino Mega 2560 has some obvious memory problems, but I don't understand why MKDuo works without problems.
Put my Configuration.h and a video showing the problem.
Marco