Alexandre,
I was working on a project, one of the etoys examples, viewing a script. Then I changed the font (type and size). I had no problem to see the code at this point. When I clicked on "Navigator" -> "Prev", I got the dialog box: MessageNotUnderstood: TTCFont>>fontArray, "An error has ocurred, you sholud probably just hit 'abandon'. Sorry!" The same happens if I go back to the project. I'm using build 239 on my B1 machine.
Yes. There is certainly a problem. I fixed it and will push the change soon. Thank you for reporting!
-- Yoshiki