You’re new to MIDI, I see.
I hate to sound persistent, but please double-check the location where you placed the script:
Your Documents folder → Steinberg → Cubase → MIDI Remote → Driver Scripts → Local → akai → mpkmini_plus → akai_mpkmini_plus.js
I also recommend resetting your MPK Mini Plus to its factory settings.
You should be able to find the procedure easily with a quick search.
If it still doesn’t work, I’m afraid I’m at my wit’s end. If I could try it hands-on, I might be able to figure it out, but…
If you don’t understand the “Bindings” section in the README, it might be a good idea to study Cubase and the MPK Mini Plus a bit more:
• Learn about Cubase’s “Quick Control”
• Learn how to configure the knob modes on the MPK Mini Plus
As for the “Optional” section, if you’re planning to dive into music production with Cubase or other software in the future, understanding MIDI basics is essential. I’d suggest taking some time to learn.
The section mentioned here deals with MIDI’s “System Exclusive Message” function.