I tried to add a new Kategory at the "Extension" tab and adding a module there. Instead of using a new language variable I used the already existing 'BOARD_CONFIG'. The installation of the extension is working fine, but everything is kind of messed up afterwards. The module and the category are displayed correctly but the module is "not accessable". The module apears a second time at General -> BOARD_CONFIG there it can't be accessed correctly.
Here is my migration file:
public function update_data()
I'm not sure if this is a bug, or if there is a convention that forbids using existing but it seems so.