If there is any error in the diagnostic page, youcan search in this page for a solution, or refer to the [Bug tracking documentation page](/peertube-plugin-livechat/issues/) if youcan't find any response.
In such case, try changing the "{{% livechat_label prosody_peertube_uri_label %}}" settings, by setting `http://127.0.0.1:9000` (assuming 9000 isthe port on which Peertube listen, ask yourinstance administrators if you don't know).
If everything is fine in the diagnostic tools, but chat windows remains empty: it can be a Websocket issue.Since Peertube version 5.0.0, there are some additional configuration to do onthe server side.Check withtheinstance administrators that they did not forgot to apply changes listed in the [Peertube v5.0.0 release notes](https://github.com/Chocobozzz/PeerTube/blob/master/CHANGELOG.md#v500).
If youcan't fix this immediatly, youcan disable Websocket by unchecking "{{% livechat_label disable_websocket_label %}}" in the plugin setting page.In such case, you should also check "{{% livechat_label federation_dont_publish_remotely_label %}}", as chat federation won't work without Websocket.