we use the NetApp SDK 5.6 C# bindings and facing now big troubles with ONTAP 9.0 and 9.1.
We can't connect to the NetApps, our customers report "The request was aborted: Could not create SSL/TLS secure channel".
If we connect via HTTP everything is fine but HTTPS does not work.
There should be no problem with the certificates because they are 2048bit long so the Windows Update which blocks 512bit certificates can't be the problem.
I would recommend to update the SDK to .Net 4.5 because then TLS 1.2 will be forced.