I copied my project file from my main pc to a laptop and would like to use the same exact Realearn setup with my TouchOSC buttons but seeing this error below when I try to launch Realearn, is there anything I can do please or would I need to setup Realearn from scratch on the laptop and configure everything [all buttons] again in Realearn on this laptop?
Looks like you haven't installed ReaLearn on that second PC. So first, install it.
ReaLearn settings are saved along with the REAPER project. So you just need to load the same REAPER project on the second PC (and maybe sync the project file with something like Dropbox). Or do you use ReaLearn on the monitoring FX chain?