Is that (C190_1,FAS2650_1 etc) the name of your 'datastores' ? It is confusing a bit, you might want to add 'ds' suffix to make them look like a datastore.
Anyway, I haven't worked on 4.5 version but it looks like you have added NetApp as 'Cluster' using admin account which seems happy looking at the screenshot, so that should be ok.
1) As a troubleshooting step, you could try instead adding 'SVM' and use the vsadmin account (unlocked) instead of the cluster, then try to select the resource group.
2) Instead of the selecting the entire datastore, try adding all the VMs (hosted on that ds) and see if there any VMs that are incompatible ?
Give it a try and in the mean time, attach the SnapCenter logs.