Thanks for doing those checks and narrowing things down.
I've sent a reply to the private message thread with a second test version.
This need to be installed over the top of 12.13 as before.
When you run it initially, I'm hoping that the problem will be gone, because it defaults to bypassing most of the changes that were in 12.12.2.
Assuming that is true, the zip I've sent has a second exe which you can run from anywhere:
This tool lets you turn on and off individual changes from 12.12.2 in the test version. When a box is ticked, the new code is turned back on.
- Most of them can be turned on without needing a restart.
- Exceptions: 02 and 11 both require a restart (i.e. fully exiting Opus via File / Exit Directory Opus, don't just close the window).
Apart from 02 and 11, you should be able to try each checkbox by turning it on and opening a new window to see if it works or fails.
- If a test works, leave it on, and try the next one.
- If a test fails, turn it off and see if the others all work OK.
That should let you go through each test quickly and see if a particular one triggers the crash.
My hope/assumption is that you will be able to turn on all of the checkboxes except one, and that one will point us to where the problem is.
(It's also possible you'll be able to turn them all on, as I've hardcoded a couple of other changes that were difficult to make optional but also less likely to be the problem.)
Many thanks, again!