ERROR 3941 for one VM

Hi All, this is my first time ever here, so thank you all in advance.

ISSUE: i recently started using VDR, it works with all my VMs "Except" the Server i need to back up,

i tried local snapshot and VDR with the nas same results.

I read about loging in and pinging vcenter, that worked fine.

I tried to run a manual snapshot as per the entries, that also failed "for that one system"

Then i read something about "Block Sizes" differences between VM and datastore;

that sounds familiar for that system i didnt setup that one server but it was the first

one we did, and i know that something related to block sizes.

QUESTION 1: how do i check if there are block size differences?

QUESTION 2: how do i fix block size differences?

Thank you all in advance!

Julio