The problem *is* the file size. There is not a minimal example, because everything works when there is less drawdot commands. There is 125000+ drawdot commands in the file.
The run ends with the message:
If you really absolutely need more capacity, you can ask a wizard to enlarge me.
mtx-context | fatal error: return code: 1
I really don't know how to "enlarge" LMTX, so my question is not about debugging the file, but rather compiling it. The current version of the file should produce no syntax etc. errors. I accidentally uploaded the wrong file twice, now it should be fixed, and you should get the same message in the console as me.