Thanks for this, lost passwordless ssh due to some permission issue, and since it happened right after installing the plugin I suspected it was the problem, just tested now on another server and it happened again, this was the error logged:
Apr 20 18:27:30 Tower15 sshd[15259]: Authentication refused: bad ownership or modes for directory /
Rebooting solves the problem it but it should be fixed in the plugin install, I can't really help with what's needed to fix it but @Squidshould be able to help you if needed.