From what I understand, the latest Logic update now supports midi out from software instruments. This is apparently causing some issues with notes being recorded twice (notably Native Instruments) From the forum:
“
When using KK3 (3.0.0, 3.0.1 or 3.0.2) with Logic Pro 10.8, all MIDI notes are doubled. This issue reproduces with all MIDI controllers when using KK3. In other words, it is specific to KK3, and not to the Kontrol S MK3. This bug has been filed as a high priority, as soon as it was reported to us. We hope to fix it this month. Incredibly frustrating for all - I will keep you in the loop as this progresses.
It appears Logic Pro 10.8 has silently introduced support for MIDI out from AU2 plug-ins. The impact of this is mostly positive: for instance, this means it is now possible for Komplete Kontrol's arpeggiator to send MIDI out of the plug-in, and into your timeline. This benefits all users of KK3 and Logic. At present, the value is limited due to the first issue. “
Whole thread here:
https://community.native-instruments.com/discussion/18363/official-known-issues-with-and-features-of-komplete-kontrol-3-0-2-and-logic-pro-10-8/p1