When I double click run.sh - gedit opens with this :
java -cp fim.jar:lib/*:conf nxt.Nxt
Somehow your desktop has assigned gedit as the default app to execute that file. Try doing it from the command line.
$ cd /home/USERNAME/fimfolder
$ java -cp fim.jar:lib/*:conf nxt.Nxt
-----------------
Tueueesen Takk!!!
Works easy
Smoerre Broe !!
Jeg ikke snakke Fimmik
joet omkring