In addition to the 5V/12V mishap around the solenoid, there's some more odd stuff going on.
The solenoid is shown as connected to GND, as is the emitter of the TIP120, so that would mean the TIP120 does effectively diddly squat.
The ATMega328P seems to have 2x 22nF around its crystal - I'm surprised it starts at all this way given those caps are 1000 bigger than they should be.
I don't see the point in having 2x100uF on the 12V rail.
There's a 3V3 regulator that supplies...thin air? with 3V3.
All considered I get the feeling the schematic we're looking at may not be the circuit as it's built. Perhaps some photos of the actual device might help...?