If you encounter this error, try the following solutions in order:
Recent versions of the BthPS3 installer offer a "Modern hot-plug" vs. "Legacy sequential" mode. If your radio isn't found during a modern install, try running the installer again and selecting bthps3 bluetooth host radio not found
rfkill unblock bluetooth
Additionally, in :
Use a companion tool like DsHidMini to handle the actual controller pairing. If you encounter this error, try the following