NI offers Komplete Start for free (no patcher required). It includes Kontakt Player, Guitar Rig 6 Player, and 6GB of official samples. These are professional-grade sounds that will never expire.
Patchers often modify system files (Windows Registry or macOS Frameworks). If the patcher is poorly coded, it can cause: kontakt 661 patcher
If you are dealing with the Kontakt 661 Patcher (likely referring to a complex patch or NI offers Komplete Start for free (no patcher required)