Hello, I have a file for which `musicxml2ly` fails, because in line 824 variable `i2` is `None`. Changing line 824 from `if i1 > i2:` to `if not i2 or i1 > i2:` fixed my issue.
I'm sorry, but I don't have time to investigate this issue more (just went in "don't think, fix it mode"). I can't guarantee that the file I worked on is correctly formed. Nevertheless, I pass you the information. I can send the file on request. Thanks again for making Lilypond ! Élie