Symfony Routing : Missing or invalid controller in Addons, modules and themes developers Posted October 23, 2020 · Edited October 23, 2020 by Vintelec (see edit history) I was waiting to be sure, but it's good: I managed to get my module working! In 188.8.131.52, my template was not good. And for the previous versions, you have to add this for the main route, as specified in the doc : _legacy_controller: AdminOrderPreparation _legacy_link: AdminOrderPreparation I got fooled because the demo module didn't have them, except that it's made for 184.108.40.206 minimum so... my bad. I thought I had already tested with these lines though but there was probably another error at the same time. I didn't test for 220.127.116.11 because I'm using the new Grid system which requires 1.7.6, so I'm going to upgrade my store to 18.104.22.168. But I think it should work too. Good programming to all of you!