Hi Max Abildgaard,
The error you are seeing is due to missing drivers of Arduino board. Try to reinstall the drivers and the issue should be fixed.
If you are not able to install the drivers, please use the attached patch files for using the manual com port workflow.
Here are the steps to apply patch:
1. Download the attached files and put them in the same folder.
2. Navigate to the folder created in step 1 above in MATLAB.
3. Run the 'applyPatch.m' file from MATLAB command prompt.
4. Restart MATLAB.
Once this patch is applied, try to set the com port manually and run hit "Mohitor and Tune" button.
Hope this helps!
Please let me know if this solved your problem.