Strange crash in Logic

I was working with the Environment and suddenly weird stuff starts happening, ending with a complete crash and possibly corrupt project file.

To be specific, I was working on a Transformer object. I accidentally typed '25' without any fields selected, so I had a rapid succession of screensets display. I switched back to 1 and then noticed that the object name had changed from '(transformer)' to '(transforber)'. Funny. Then I noticed that the instrument track it connects to(via a Monitor object) had also been renamed. I don't recall what it was but I'm confident that some letter had changed to a 'b'.

I shrug, ignore and move on to some work with bus auxes. Then I notice the colour of one MIDI region within one specific folder had changed to black and the output setting of an auxiliary track had changed to a Bus from Stereo Out. I fixed that and then decided to fix the region color, so I hit Option-C and start selecting colors. All of a sudden Logic freezes, then spinning beach ball, then crash.

Well, I restarted Logic with the same project. Then I get this error message which I've never faced before.

The error message

I hit repair, the project loads, no issues. But when it opens, I see that the coloured region now has no MIDI data, and an alias pointing to it is now orphaned. Clicking OK instead doesn't change anything that I saw.

I really don't know what to think. I opened the console and retrieved the crash log from the Library, and besides the system status and thread dump, it said

Exception Type: EXC_BAD_ACCESS (SIGABRT)

Exception Codes: KERN_PROTECTION_FAILURE at 0x000000013fbf900a

Crashed Thread: 0 Dispatch queue: com.apple.main-thread

 

Application Specific Information:

*** error for object 0x13f656400: incorrect checksum for freed object - object was probably modified after being freed.

I reopened a backup file saved a little before the crash, and that one gave me the same error message. Also, I noticed that the Mixer layer in the environment had a few strange errors of its own:

Mixer layer in Environment

Note the last two instrument names.

Last few weeks I've been having trouble with this particular project. At first I had a few crashes which were nothing specific, so I just backed up the project folder and moved on. Logic crashes occasionally and usually I know how to handle it. But it's never been like this. Now I've lost a valuable MIDI region and heaven knows what else, I haven't looked much.

Any suggestions?

Creating a new empty project in Logic using my iMac's speakers seems to create no issues. Tried some MIDI recording, now I'll try messing around with the Environment to see if I can replicate the problem.

Some Googling reveals that warning messages of the type which I've received often come up when

1. Projects are transferred, or when the folder gets corrupt in any way - especially when filenames get longer than 30 characters.

2. Something goes wrong with the Environment, or you have objects/cables, or simply problematic cabling.

So I'd do well to check my project assets once and see if anything's awry or missing. And I'll probably reopen a copy of the corrupt project and see what's happening with the Environment.

So I filled up the project with long pads and MIDI aliases, etc., trying to replicate the demands of my problem project. Then I attempted an Environment cabling similar to what had caused the earlier crash, and Logic crashed when I tried to cable from the Mixer layer to a layer I created by dragging. Although this was a normal "Logic Pro has unexpectedly quit" error and I lost no data, it does show that something is fishy with the Environment.

I think I'll still try to complete the cabling in the test project and see whether it works smoothly. Another thing I've been contemplating is to trash the Logic preferences and let Logic rebuild them on start - I've seen this suggested in many places. But I think I won't do that until I finish with the test project's Environment cabling.

In case anyone is following this thread and is wondering what crazy cabling could possibly have caused errors, here it is:

The MIDI path in question

I plan on connecting a software instrument channel to the input of the 'Pre' monitor, and then cabling the output at the 'Post' monitor to another instrument channel. The Transformer object filters by pitch range and applies a 'Rand+-' operation to the velocity.