Q Light Controller+

Hey there,

I am on MacOS Sonoma 14.0 the problem is the same across QLC+ versions and on Windows.


I've been using QLC+ for quite a while now and like everyone else who uses it I absolutely love it and even if I didn't I don't have the budget for anything else. I've noticed this bug before but because I wasn't programming such complicated stuff it hadn't bothered me until now.

I use IAC Midi driver coming out of Ableton and into QLC+ with Control Change messages for each channel on my 7 lights that I own. This works well, except for one problem. Sometimes the IAC driver hiccups. I haven't figured out what causes it yet. I have 20 songs setup in Ableton and all 7 lights and their channels on slider matrices in virtual console (all on level mode). I don't use any QLC+ functions themselves, everything is through Ableton and the sliders. I noticed it in a couple of songs when some looks would sort of freeze and then come back when more movement is detected but as you can see in my video, I created a test loop to run during setup not only to brighten the area but make sure all the lights and channels are working properly. Each channel goes from 126 to 100 every bar and as you'll observe in the video every about 20 seconds control will return and QLC+ will update the midi positions. For some reason QLC+ and the IAC driver do not like this specific circumstance AT ALL. I have other looks in my show that move faster and some that move slower and as I said before theres a few that get stuck. The setup is all fine and dandy, I have all the sliders on level mode, but on some I have monitor selected channels on and some off, I also have catch up off on some to try and troubleshoot my problem here with no avail. You can notice in the top right of Ableton there is a constant yellow/orange square and that's saying that the midi is being sent, so I imagine the problem is with IAC or QLC+. Does anyone else have a setup like this and do you have the same problem or any suggestions at all? I'm not afraid to make a copy of my workspace to fiddle around with as I've done that multiple times before.


Thanks for your help in advance

I noticed that (in most cases) you boxed, both "Catch up with the external controller input value" and "Monitor the selected channels and update the slider level".

As you are not in a situation where you are "controlling a few sliders in different pages of a Frame with a single fader of an external controller," (in fact all your frames are single page) you don't need the "Catch Up ..." option.
I suggest you unbox this option on all your sliders.

Where you use the "Monitor the selected channels and update the slider level" , the channel you selected is the same as the channel you selected (on the General tab) as External Input.
I Guess this is where you create a Dead Lock Situation: monitoring the same channel that is controlling you.

In the manual you can read: "If you interact with the slider while it is monitoring some DMX channels, it will switch into an override state, .....".
In your video you can see "Red Crosses" on all your sliders, meaning that they are all in override status.
I suggest you unbox this option also (or at least remove the selected channel).