Playground demos fail with disabled Referers

[Bilge]

Summary

I cannot see any playground demos on any page in Firefox. They work fine in Chrome.

URL

https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements/details

Reproduction steps

1. Go to page

Expected behavior

See demo.

Actual behavior

Demo fails to load.

Looks like there’s a problem with this site
https://7263c978-506a-40b7-abb0-92a200d06320.mdnplay.dev/runner.html?state=jZBNTsQwDIWvYoUtmQEJNqGaFTdgSVm4jacN5KdqXFE0mruTTFoKiAWbRHnP fzsk jZWaFEpYnR2HioPUAVJ dw/Dg8FrHar0J2n4Ij7o3vIDq0FsiHqeuBA1BscSBoMU5owQc2Le1qX 03uLgWbYyp4SLBKSObMGoaFdwOM8RgjYYrRHzYLDmiNlNUcDfMF3lArVMEBTe7e3Lrmaxz7Wu/xC3wY/As38l0PauEs/oCSH5nvAJZvsqN8Bu QpfEz2Eg/1LQ/yn8kWWZpgnMwf05b8n1VfENnFb3mjeXbk1HnCznl5klY9OQTjL35CjvFsc3cf4E sent back an error.

Device

Desktop

Browser

Firefox

Browser version

Stable

Operating system

Windows

Screenshot

Anything else?

No response

Validations

• I have read the Community Participation Guidelines.
• I have verified that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• I have checked that this is a concrete bug. For Q&A open a GitHub Discussion.

[caugner]

Thanks for reporting!

The screenshot suggests that your Firefox is not sending the Referer header (which we use for safety reasons, to ensure that we execute the code only in iframes on MDN, see the corresponding code).

@Bilge Are you using a Referer extension, or have you modified preferences in your about:config?

[Bilge]

I have network.http.referer.XOriginPolicy set to 1 to disable referer in cross-domain scenarios, for my privacy. You should find another solution to your "safety" problem, since relying on such a header is not practical and other websites do not break in this manner.