## Troubleshooting
### 1) General
1) Restart the connected devices and then the program
2) Check the log file, which might contain helpful information.
   It is located in the cache directory, usually in `~/.cache/cpdctrl-gui`.
3) Ask superuser

### 2) The Arduino/LEDD1B does not work
1) Make sure the Thorlabs LED is plugged in, turned on (turn the dial to a non-zero value) and that the switch is in the **TRIG**er position
2) Reset the Arduino by pressing the white button on the top and restart the program
3) Unplug and replug the Arduino and restart the program
4) Re-upload the code (see section "Technical Information/Arduino Code")