I’ve seen a couple posts about this same error, and the 1st response is always restart nginx. I have restarted the service multiple times, along with rebooting the entire server multiple times. Every app I try to install now gives the same error. I have tried multiple browsers, clearing all cache and cookies. I have tried 3 different internet services.
Is there a limit on how man apps yunohost supports? I currently have 15 installed, 2 of which give the too many redirect errors. The other 13 are fine. I can create a new one right now with a random app and random sub domain and always get the error.
In addition to your update of the first message with said template, add NGINX logs right after you trigger these errors. Are you in a special configuration (VPS/VPN/multiple subnets…)? Logs are to be shared from the NGINX service page, with the “Share with YunoPaste” button.