Thank you for the detailed explanation. Now it’s clear that the issue is not caused by VICE but by a bug in the PRG generated by Larry’s FLI Converter v187, where the BASIC stub is missing a zero at $081B. That explains why newer versions of the converter work fine. I’ll try fixing the file manually as you suggested. Thanks again for clarifying this.
VICE (x64sc) freezes with PRG from Larry's FLI Converter V187