When trying to access iconfinder der following message pops up:
Verbindung zu https://www.iconfinder.com/xml/search konnte nicht hergestellt werden
When entering the above URL into a browser the following is displayed:
Invalid API key.
Even when i sign in to iconfinder this error persists. I can generate an api key for me, but i don't know where to enter it in yEd.
IconFinder does work in yEd 3.11.1. Either IconFinder is blocking your IP (try https://www.iconfinder.com/ in your browser to test that) or your machine is blocking yEd from accessing IconFinder.
The URL https://www.iconfinder.com/xml/search does never work as is; it requires additional parameters because it is meant for programmatic access to IconFinder.
In version > 3.20.1, iconfinder is not shown.
yEd's IconFinder client has been removed as of yEd 3.21. IconFinder no longer offers the service interface required for this feature. (See also the yEd release notes.)