After adding the very first ssh-credential in a newly installed jenkins as a "system credential" during the "add a node" process, we get the error message:

"The selected credentials cannot be found".

There are no credentials available to selected in the dropdown, apart from a credential called "none", which makes no sense.

It appears that a credential was created in a broken state that is not possible to use.

At this point the "add" button is broken.