The app shows a black screen

If Containly stays black in the browser or as the installed app (PWA), one of these causes is almost always behind it.

In the browser over plain HTTP

CONTAINLY_SECURE_COOKIES=true is set, but you open Containly over http://. Set CONTAINLY_SECURE_COOKIES=false in .env, restart with docker compose up -d and reload the page with Ctrl+Shift+R. true belongs behind a reverse proxy with HTTPS only.

The app cannot reach the server

The installed app needs your Containly server for every page. Typical reasons:

• You are outside your home network and the VPN is off.
• A firewall or the reverse proxy blocks the address.

Open the same address in the phone browser. If that does not load either, fix the connection first (connect the VPN, check the firewall and the proxy). If the browser works but the app does not, close the app completely and open it again, or install it again from the browser.

After an update

Reload the browser tab. Close an installed app and open it again.

Since Containly 2.3.0

Instead of a black screen the app shows "Containly is not reachable" with the likely reason (offline, no answer, blocked, proxy sign-in, server error), tips and a retry button. After an update an old tab reloads once on its own. So updating is worth it.

If none of this helps, open a topic with your Containly version, browser or phone, and whether you connect over HTTP, HTTPS or a VPN. More in Troubleshooting.