the issue showed up again, this time outside of a function. The computer was only moderately charged, but the change of behavior occurred after I loaded a 25MB text file into Notepad++. Should I change something in the JVM settings?
To be honest, I really have no clue yet what's going on here (I can't remember to have encountered a similar behavior before).. If you want, you could once again try to simplify the example again as much as possible and send it to us. Of course it would be great if you manage to reproduce it on any other machine you can get your hands on.
You are exclusively using the BaseX GUI, right? Does the problem also happen on command-line?