Before we fix it, you need to understand the root cause. Most "How to install Kontakt libraries" tutorials on YouTube assume you are using or a fully licensed, standard Kontakt Player library.
Title: Bobdule Kontakt Tutorial — Not Working (Troubleshooting & Verdict)
: If you are trying to replace a stock DAW plugin with Kontakt and no sound comes out, try deleting the MIDI region and creating a fresh one, as MIDI data sometimes "locks" to the previous instrument's parameters.