Created attachment 157145 [details]
error details from kdenlive crash on Save As

SUMMARY
***
NOTE: If you are reporting a crash, please try to attach a backtrace with debug symbols.
See https://community.kde.org/Guidelines_and_HOWTOs/Debugging/How_to_create_useful_crash_reports
***
Sorry, that link says it is not relevant to Mac computers.

STEPS TO REPRODUCE
1. Start a new project, basing details on first clip imported, accepting suggested transcode. 16x9 ratio, variable framerate transcoded to 30 fps.
2. Add another video clip, accepting suggested transcode.
3. Do File->Save As and successfully save a .kdenlive file.
4. Drag the first clip to the timeline.
5. Replace the audio of that clip with an improved version made with Audacity.
6. Insert an image as a background video track below the main image, so the main image can be transformed and moved partly off the screen without leaving a slice of black.
7. Add a 3x4 image in a video track above the main track, transform it to move it to the left margin. This leaves the speaker on the right-hand side of the screen, and the slide she is talking about covering most of the screen.
8. Stretch the image to cover the duration of the talk about the image in the main track.
9. Transform the main track to move it left and right as the speaker moves a bit, to keep her on the right-hand side of the screen and not obscured by the slide she is talking about.
10. Do File->Save As to a modified filename in the same folder as the video clips. Successful save.
11. Repeat steps 7 to 10 several times, copying the transform effect from an old image to the new image each time. Save As works properly.
12. Do File->Save As and the program crashes, displaying a lot of details that it says will be sent to Apple. I'll attach a file of those.


OBSERVED RESULT

When the program crashes, the file I was trying to save is not written.
When I relaunch the program and load the last-saved .kdenlive file, it offers to recover unsaved changes.
For some images, the program reports an error dialog when I import the image, and the detail is that the image is too small to make a proxy file. (Setting was for 700 px.) Version 22 of kdenlive just said it was unable to make a proxy file from that image.
I changed the default settings and the settings for the project so that it did not try to make proxies for any images, and after a crash this change was remembered.

EXPECTED RESULT
File->Save As would work properly as has been the case for several videos I have made with earlier versions on my Mac

SOFTWARE/OS VERSIONS
macOS:  Ventura 13.2.1

ADDITIONAL INFORMATION
kdenlive version is the nightly build from 
https://binary-factory.kde.org/job/Kdenlive_Nightly_macos/
Number 1410 of 2023-03-09. 
I moved to this version because the normal stable release, 22.12.1, was crashing the same way.
I have attached the debug information that I could find, and have uploaded the .kdenlive files that I was able to save to a folder in Google Drive, along with a rendering of the video, so you can see what the transform effects do. Here's the link:
https://drive.google.com/drive/folders/1ibi-iRBUtBnS_wRr7Ro1SzHF27p6QVWR?usp=sharing

There is a bug report that seems similar at
https://bugs.kde.org/show_bug.cgi?id=466561
In that one, 4ironman7@gmail.com changed the save location, which I did not do.

I hope someone can suggest some work-around for me, and the developers, so generous with their time, can work out what is going wrong and fix it :-) (Thanks, developers, for a wonderful program!)