Unable to SSH into an Avamar node after upgrading to 7.5.1?

If you're getting the error "Server unexpectedly closed network connections" after upgrading Avamar to 7.5.1 (from 7.4.1-58 in my case) there is an easy fix!

Download and install the latest version of PuTTY. You're looking for v0.7.

Get it direct here:

https://www.chiark.greenend.org.uk/~sgtatham/putty/latest.html