I removed the cause of the crash by having the user who was experiencing the crash check it out.
[img]{STEAM_CLAN_IMAGE}/41927856/fc63ee52d289a20eb9c9f3c85e82e20ea7ebaf6d.png[/img]
I had a very hard time because the crash did not occur in my environment, but I suspected that the performance improvement efforts made in version 3.3.2 had some negative impact.
So I reverted the source code to version 3.3.1 and implemented the "Unity animation clip export function" and "preset character changes" again.
I have already confirmed that it works correctly with the help of users who actually experience crashes.
It was a very hard work weekend.
Hope you have a good weekend.