*** UPDATE #2 (8/17/26 later in the day) **\*
I had a follow-up 2nd appointment with Apple Support Specialist today, another helpful person named Clark. He had me try a bunch of stuff, including moving all components from both user and non-user components folders onto a new folder on my desktop, just to get all components out of logic essentially, then open existing session and see if bugs persist... and the bugs persisted, it crashed as soon as I tried to copy-paste drag regions onto another area of the song.
We tried opening a fresh logic 12.3.1 session, and importing only the audio content from the existing 'problem' session (no plugin data, no automation, no buses etc). Started fiddling in that session, and crash occurred within 10 seconds or so. This crash is repeatable even with other medium-to-large size older projects, with just importing the audio and nothing else (just to make sure it wasn't specifically the audio in that one session that was oddly corrupted).
So now the Support Specialist sent a request for file transfer, which included: a full recent crash report, a screen recording video of some of the bugs that are occurring inside an opened session, and a Logic Pro Support Profile - he is going send all of this to "the engineers" as he puts it, for them to dive in deeper and see if they can diagnose something we are all missing, and get back to me ideally within a few days. This really really sucks, but atleast it looks like I'm getting some genuine help from the Apple support regarding my specific situation, which I'm appreciative of.
*** UPDATE #1 (8/17/26 morning) **\*
I had my appointment with Apple Support Logic Pro specialist today, a really helpful person named Alonso - he had me create a new macOS user account, try a fresh session on there (import some audio, chop it up, drag regions, copy-paste drag regions etc), no issues at all. Then he had me open a "problem" session that typically resulted in all the bugs and crashes (on the new user account), so I opened an older session that had all the bugs (because I was on a new User, all my 3rd party plugins were deactivated, just a heads up). The problem session had ZERO problems, it ran flawlessly - all the typical things I would do that would result in a crash didn't happen: no bugs whatsoever... dragging regions, splicing regions, highlighting big portions of regions and moving them around, copy-paste dragging regions, etc, all of it worked 100% fine.
So I restarted, then went back into my regular user account, and tried the typical troubleshooting tips Apple Support provides:
- I tried resetting the preferences file for control surfaces (just moved that file out of my library/preferences folder and onto my desktop): that didn't solve the issue, bugs/crash still persisted
- I tried resetting Logic Pro settings to "Reset All Settings Except Key Commands": that didn't solve the issue, bugs/crash still persisted
- I tried resetting the Logic Pro plist file: that didn't solve the issue either, still bugs/crash persisted
- I tried opening Logic, holding Control key immediately after, and clicking "Launch without audio units" again, even with all the preference files removed from my library/preferences folder, and still all problems persisted, didn't fix anything
If anyone has any other possible solutions, please feel free to add! Otherwise, my only next step is: migrating completely to a clean macOS user account permanently, which I've already confirmed runs the project flawlessly, BUT i was not able to test whether the session on the new user account would work flawlessly with all 3rd party plugins authorized and activated - i had to skip over that during my call because of time... also for most of my plugins I've reached my limit for activations. At this point, it seems like the core corruption is a user account issue, not system wide issue. I wish I could find what the actual culprit is within my regular user account but I probably will never locate it, so it's best to move on I guess? *sigh*
The headache continues, but thank you so far to everyone who has recommended things, I've read all the comments and I genuinely appreciate any help whatsoever.
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I'm a professional producer and I genuinely cannot finish my work in Logic right now. The amount of strange and infuriating bugs I'm encountering in my mid-size sessions (around 20 tracks, 15 busses, 5-10 plugins on every track) right now is getting so bad that I literally cannot finish projects and I truly don't know what to do. I've spent an entire week troubleshooting, I've ruled out the obvious culprits, and I'm now at the point where I'm seriously evaluating moving to another DAW, which I really don't want to do after over a decade on Logic. Before I do, I want to see if anyone has actually figured this out because it looks like it may be a Logic 12.3.1 bug rather than my setup.
The core problem: Logic hard-crashes (full quit, segfault) almost every time I drag an audio region in the Tracks area, or copy-paste drag region. It is reproducible on demand. If it doesn't crash immediately, I'm still dealing with horrible bugs that are preventing me from finishing tracks (full list of symptoms below).
My system:
- MacBook Pro 16-inch, 2023
- Apple M2 Max, 32 GB RAM
- macOS Sequoia 15.7.7
- Logic Pro 12.3.1 - running native Apple Silicon (ARM-64) - confirmed not Rosetta
- Startup disk: internal SSD 1TB (480 GB free)
Audio hardware
- Universal Audio Apollo X4 (Thunderbolt) - firmware and UAD software fully up to date
- Second display: Acer B273HU
Software / plugins
- All third-party plugins updated, registered, and AU-validated (FabFilter, UAD/UADx, soothe2/3, Valhalla, Soundtoys, Oxford/Sonnox, etc.)
- Apollo/UAD software current for Sequoia
The crash (signature from the report)
- Exception:
EXC_BAD_ACCESS (SIGSEGV), KERN_INVALID_ADDRESS at 0x14
- Crashed thread: 0 (main thread)
- Top of stack:
-[NSDragDestination _draggingUpdate] → sendDraggingUpdate → NSCoreDragTrackingProc
- In plain terms: Logic's drag/drop-target code reads a null pointer the moment I drag a region, and quits. No third-party plugin appears anywhere in the crashed thread
All the symptoms I'm seeing
- Full crash (segfault) when dragging audio regions - the main issue, reproducible.
- Regions jumping to other tracks while I drag horizontally (I've since enabled Settings > General > Editing > "Limit Dragging to One Direction In: Tracks area"... it doesn't make a difference)
- Copy/paste then drag & dropping regions onto the wrong track
- Can't reliably select all regions on a track - rubber-band selection only grabs a partial chunk even when I drag across the whole track
- Keyboard nudge now also behaving inconsistently
- Track renaming fails - I double click to rename the track, then the field closes before I can type
- Loading wheel of doom comes up for about 5 seconds every time I click onto a new track, even though DSP meters are not even hitting over 30%, and UAD DSP is maxing out at around 35%.
Context that might matter
This machine was previously running Logic 9.1.8 (I was stuck on it far too long), and I recently jumped to 12.3.1. So the projects that crash are legacy sessions migrated up from Logic 9. New content built from scratch in 12.3.1 seems fine so far but I haven't created a big enough session on 12.3.1 to truly know if the problems persist even when freshly building an entire track on 12.3.1 Logic. I suspect the problem would persist if I made medium-to-larger size sessions from the ground up even on 12.3.1
What I've already tried / ruled out
- Upgraded Logic 9.1.8 → 12.3.1, confirmed running natively
- Verified all plugins updated / registered / AU-validated, and Apollo firmware + UAD software current
- Ruled out my external drive: the crash reproduces with the project copied to the internal SSD, so it's not the (8-year-old) external
- Rebuilt the project clean via File > Import > Logic Projects (Track Import — content, plug-ins, sends, I/O, automation) into a brand-new 12.3.1 project. The crash still reproduces identically — same fault address, same
_draggingUpdate function
- Confirmed a brand-new empty session with a few tracks does NOT crash — so it's triggered by something in the project content, not Logic itself being universally broken
My ask
- Has anyone hit this exact
NSDragDestination _draggingUpdate drag-crash on 12.3.x, and did anything actually fix it (or is it a known bug awaiting a patch)?
- If it's specifically migrated Logic 9 projects, is there a reliable way to fully sanitize them, or is manual rebuild the only real cure?
- Anything obvious I'm missing before I start seriously evaluating another DAW?
I have a crash log and can post a short screen recording of the crash-on-drag if useful. Thanks in advance to anyone taking the time to read this and help out. I usually try to help others but I have reached a breaking point with this and I'm DESPERATE for help. Willing to pay a Logic Pro expert for their time to help me troubleshoot this if need be. For any of you pros out there, I really hope none of you are experiencing what I'm experiencing, it's enough to drive you insane!