Yippy.com is using a strange method to attempt to allow you to install a search engine - it is using sources and relying on data from mycroftproject.com. Unfortunately for them, that method of installation is not longer supported which is why it doesn't work.

It is a bit strange that they chose to rely on a third-party site, rather than offering the search engine description themselves - which they can do themselves via OpenSearch or Add-ons.

Yippy.com need to update their site to use the normal supported OpenSearch discovery or add-ons method of defining search engines.

Yippy responded to me this morning:

To: E M Giasson:

We just updated the site to allow the direct OpenSearch installation of the Yippy search engine within Firefox this morning. Please let us know if it is working for you.

Thank you,

Yippy Support

I still can't find it. How shouldI be adding this?

I got it. The three dots on the URL bar let me add it.