As the title says, I wanted to send a crash report, but it kept failing to do so. So, I’m sending it here:
Audacity Crash Report.txt (211.2 KB)
So there have been similar reports in both 3.4.0 and 3.4.1: 3.4.1 Crashes trying to open 3.3.3 .aup3 project · Issue #5568 · audacity/audacity · GitHub
This bug has been corrected in development and the fix should be released in 3.4.2.
Until that happens, revert to 3.3.3: Old Audacity versions download