line 1381 of assembl.c, jmpoffset has not been initalised under case arg = 0.

this is seen when running the sample main.c with runtime checks enabled under visual studio.

easy fix is to add jmpoffset = 0 right after declaration, i did this on line 680.

are you talking about the assemble.c in the sources that is on main site
they belong to version 1.04 the release version is 1.10
so it can contain some problems