If you try and add a Hyper-V host to your Veeam backup infrastructure, without having the correct ports open on the host, the installer will pause for some time on the “Detecting previously installed components” stage before finally returning a “Network path not found or invalid credentials” error. To allow the correct communications you need to open certain (inbound) TCP ports on the host. The full detail can be found in this Veeam KB article, but for a simple Hyper-V host connection I needed 135, 137-139, 445, 6160, 6162, 6163, 2500-3300, 49152-65535.
Veeam B&R – “Some backup console’s plug-ins must be updated to the latest version” on every launch
A recently updated Veeam B&R console install then produced a rather annoying pop-up every time it was launched....
