ADC Interrupts not working

I tried the example code MarkT posted in the thread "Example of driving ADC and DAC from timer for regular sampling", and I've made a few changes to define the sampling rate and use the A7 and A6 ADC inputs instead of A0, I've also omitted the DAC part, but the code is stuck somewhere, and I can't find out why?

Could you help me, please? I can't find anything wrong in this code.

adcExample.ino (3.42 KB)