Errors / Network errors

net::ERR_BLOCKED_BY_ORB

The browser blocked something it loaded from another website because it was not what the page said it would be.

That script, image or style does not load.

Why it happens

• Opaque Response Blocking: a cross-origin request made as a script, image or style got back something the browser will not hand over, typically HTML or JSON where a script or image was expected.
• Often an error page: the third party answered a 403 or a 404 page, or a bot-check page, to a <script src>.
• A wrong Content-Type on a third-party asset.

How to fix it

1. Open the URL directly and look at what comes back; if it is an error or a login page, fix the URL or the account behind it.
2. If it is your own asset, serve it with its correct Content-Type and X-Content-Type-Options: nosniff.
3. Some vendors block data-centre visitors; seen only by a checker, it may not affect real visitors.

Whose problem it is

Either the site's own code or a third party's, depending on where it comes from.

Often seen with

• Refused to execute script: MIME typeThe browser asked for a script and got something else, so it would not run it.