I had also problems with german special characters also on two other systems: Wd Mycloud NAS542 I was able to solve the problem with the following steps: Install Entware Install Entware Busybox, MC and unrar Moreover I checked that the following lines are in /opt/etc/profile: export LANG='en_US.UTF-...
I saw your comment. Nevertheless your wrapper is working in my environment (Fritz!Box with freetz-ng). If the wrapper doesn't work in your environment en_US.UTF-8 might not be available on your system. In this case you should find out which locales are available.