Did you follow the [installation instructions](https://tttapa.github.io/Control-Surface-doc/Doxygen/d8/da8/md_pages_Installation.html) for the dependencies?

[dchstudios]

Did you follow the installation instructions for the dependencies?

Also, don't include MIDI.h, it's a different library, and it might interfere.

Originally posted by @tttapa in https://github.com/tttapa/Control-Surface/issues/83#issuecomment-573849568

[dchstudios]

I still can't get the <Encoder.h> file to be seen when used in the #include code. I tried installing the Teensy libraries that it suggested (all), deleted it's version of Midi.h as per above. I see that the Encoder.h file is buried in the "hardware" folder of the Teensy ->C:\Program Files (x86)\Arduino\hardware\teensy\avr\libraries\Encoder , does that make it inaccessible if I'm not using a Teensy hardware board specific? e.g. I'm using a Seeed XIAO so I have the board loaded for that. So then I tried just copying the whole Encoder file from within the hardware library folder of the Teensy, and put it at the higher level with the other regular Arduino libraries -> C:\Program Files (x86)\Arduino\libraries. Still a no go. <Encoder.h> "cannot be found"

[tttapa]

You are not installing it correctly. The process is the same for pretty much all libraries:

Go to the GitHub page for the Encoder library, click the green "Code" button and download the repository as a .ZIP file. Then go to the Sketch > Include Library > Add .ZIP Library menu in the IDE Navigate to your downloads directory where you just downloaded the library. Select it, and click Ok.

The libraries included with the Teensyduino installer are only for Teensy boards. Don't use Teensyduino unless you're using a Teensy.