>> What version of 9vx are you using? > > I'm using version 0.12, from here: https://swtch.com/9vx/
This is a pretty old version (2009), which have known issues. Later, Yiyus and Ron Minnich made a lot of improvements. I would recommend you to use this repository: https://github.com/0intro/vx32 -- David du Colombier
