Pro Tools is unique in that the software is inextricably linked to the ProTools hardware. Thus, one is working in a very controlled environment. This is beneficial because of stability and reliability, but also creates some limitations. The main limitation is the adjustable buffer sizes in the ProTools environment and the inability to assign memory.

•Options Button in ProTools:
Some reported that the "Options" button remains selected within the Kontakt Player. This occurs after the Options Window has been selected and subsequently closed. Because the button remains "selected" this causes any mouse-click on the Kontakt Player window to reopen the Options Window and no other actions are possible.

USER WORKAROUND: Submitted by Brendon McDonnell: Select the Window and drag it to a different location on-screen. Closing & re-opening the Kontakt Plug-In Window does not de-select the Options button; the Kontakt Player must be uninstantiated and then re-instantiated to eliminate this behavior.

(from garritan.com)