When trying to load an Ensemble which requires the full version of REAKTOR from the MASCHINE 2 or KOMPLETE KONTROL Browser, the following REAKTOR 6 activation request window may appear: 
This happens if both the full version of REAKTOR 5 and the Player version of REAKTOR 6 are installed on your computer. To solve this issue, follow these steps:
- Open the MASCHINE 2 / KOMPLETE KONTROL Preferences.
- Go to Plug-ins > Manager.
- Uncheck the option Always Use Latest Version of NI Plug-ins.
You will now be able to load your REAKTOR 5 Factory Library or User Ensembles in MASCHINE 2 / KOMPLETE KONTROL as expected. Ensembles requiring REAKTOR 6 Player (eg. FLESH, BLOCKS WIRED) will still be opened with REAKTOR 6 Player automatically.