Hi Pere,
The message means that the board cannot communicate with one or both of the touch sensors on the top of the D-Box. First, make sure the touch sensor cable is connected properly to the board (it's the 4-pin one with black/red/yellow/green wires) and to both touch sensors. Especially make sure that it is not inserted the wrong way around or off by one row in either of the sensors.
If that doesn't solve it, you can go to the terminal at the bottom of the IDE (click where it says root@bela ~/Bela#) and type:
i2cdetect -y -r 1
This will list the connected I2C devices. If the sensors are connected, they should show up as 18 and 19. If you see nothing, or if it takes a very long time to print anything, then check the I2C cable connections again, and maybe try each sensor individually to see where the problem is coming from.
