I can't reproduce in 1.37/current master. What you have is [zero-width-space (U+200B)](https://en.wikipedia.org/wiki/Zero-width_space) followed by a newline (U+0A). Nothing too weird here, and nothing that I would expect Geany to crash on.
@poikilos do you have any plugins enabled? In any case, could you try with a clean configuration to see if you still reproduce (you can use `geany -c /tmp/temp-conf`)?
FWIW, here's the bytes: ``` ``` (yes, not much to see, but it's there)