Logic Pro: Error while trying to synchronize Audio and MIDI


Logic pro X gives me such error (not always but often):

Error while trying to synchronize Audio and MIDI.
Sample Rate 36 915 recognized.
Check conflict between Logic Pro X and external device.

I am not sure, but I think it’s when I have set multiTimer. But multitimer is in my AudioProcessorEditor, so it has nothing to do with AudioProcessor. But in my timerCallback I use and manipulate myAtomicIntValue which is member of AudioProcessor, and I also manipulate that value in processBlock.

Could it be really the reason of my error? How to avoid that?


This usually happens, when you stall your audio thread. I see this most of the times, when I continue after a breakpoint in processBlock().
If you see this in “normal” operations, something is smelly. Just setting an atomic or even 10 shouldn’t be a problem. But be aware, that there is some synchronisation at work, so be careful.
The most likely is IMHO, you print into the console from your processBlock(), e.g. using DBG. This is a blocking operation from the OS, since other processes could use the same console. Try, if the problem is till there after removing blocking operations.

Hope that helps



continue after a breakpoint in processBlock()

Did you mean breakpoint during debuging? Or is there any other type of breakpoints which I don’t know.

By the way. Fortunately it looks like - not for sure but seems - the error happens only when I am in debug mode. But it still strange for me, and when I get that error I am always little bit sad :slight_smile:

But hopefully it’s because of debuging and all those breakpoints.


I’ve had the same experience, I’ll get this in Logic X every so often in our debug builds but not once we make a release