I wanted to update my TP-Link TL-WR1043N/ND v2 from 1.6.2 to 1.8.1. Basically the update works. But when I want to install plugins (Tor, German, theme), I can install some and and sometimes all of them but can't access them in the menu on the left. Sometimes I can access one or two but never all. Most times uninstallation is not possible so that I have to upload firmware again and start all over. There is no pattern recognisable when a plugin is installed and shown on the left and when not.
I remember that this was an issue already when I installed 1.6.2 some years ago. Back then I tried many time to get my plugins installed and running. This time I tried about 10 times and getting tired.

Is there any work around maybe via ssh and command line? How to install plugins from command line? Can I force the system to scan installed plugins and to rebuild the menu?
Thank you.