Display an helpful error message when Privacy protections may break the app preview pane

[Akryum]

🌈 Feature

In some cases, Privacy protections from the browser may break the app preview pane. Currently it displays nothing (blank). It would be nice to have an error message instead.

When the App Preview iframe doesn't load, display an error message like:

App couldn't be loaded
Please check you are not blocking third-party cookies

To reproduce this, you can go to Firefox settings, under the Privacy & Security > Content blocking section, select Custom and then select Cookies > All third-party cookies

[arthurdenner]

@Akryum, is there a way to know if this config is active?

[Akryum]

I guess an error is thrown like in the OP?

[github-actions]

This issue is stale because it has been open many days with no activity. It will be closed soon unless the stale label is removed or a comment is made.

[github-actions]

This issue has been automatically closed because there wasn't any activity after the previous notice or the stale label wasn't removed.