It should be clear that the Evergreen Jenkins plugin is not designed to be installed on a non-evergreen Jenkins instance.
But currently for some reason, despite the fact I wrote
Jenkins Evergreen Plugin - Note: you should generally never install this plugin yourself.
In the plugin manager, it looks like:
The end of that message should be visible. I suppose there's a tokenization that cuts after the hyphen or something. Probably we just remove it and that's enough.