it requires 3.0 version of ssh_remote plugin, i am having 3.0.1 version.
Sadly that was a different issue manifesting the same way.
The issue you (and others) are currently hitting happens when some of the hosts interfaces doesn’t have an IP. It should be fixed by this change. Foreman remote execution 3.3.1 containing it was just released to rubygems, although it will take a bit more time until it reaches the repos.
Until the fixed version lands in the repos, in theory going into the UI and just setting a random IP for the offending interface might work and deleting the host afterwards might work.