Facebook Messenger is not loading
There are a few known situations where Facebook Messenger can have trouble loading. Please check to see whether your issue is displayed below and then follow the suggested steps. If your issue is not listed below, please contact HelpShelf support for further assistance.
I'm using Safari 12
Currently, Facebook Messenger is currently unstable with Safari 12. Please note that officially, Facebook Customer Chat is in beta mode, hence the current lack of support for the latest version of Safari.
If you see a console error like "Refused to display *** in a frame because an ancestor violates the following Content Security Policy directive: ***"
Check that the domain of the page the plugin is being rendered on has been whitelisted. Also make sure you didn't set the Referrer-Policy header to no-referrer.
The Firefox Facebook Container Add-On prevents the plugin from showing up.
Remove the add on if you want the plugin to render.
I'm using Firefox desktop private browsers (version 63 and above) or Firefox mobile browsers
These browser block content tracking by default which will prevent the plugin from rendering. Turn off content blocking (click the grey shield in the search bar) to see the plugin render.