to reproduce problem easiest you can add 1 kontakt in reaper and have no instrument load. now enable in option "midi script generate note only". now add another kontakt below the kontakt you add before. in this 2. kontakt add for example from kontakt factory selection the first one (its classic bass). but problem happen with all kontakt instruments or other VSTi. the 1. kontakt send when key on midi keyboard is release another note and, and never send note off. the notes hang. have other this problem too, or is there maybe a setting ?