IsilonSD edge unable to deploy com.vmware.vim25.InvalidRequest

HI , I've seen people in past post similar errors but no solutions. I'm using vpshere 6.7

I'm trying to deploy a 3 node SDedge cluster for a proof of concept. I've deployed the management server without issue, uploaded the image for 8.1.2 and registered my virtual center.

When I create my IsilonSD cluster  I get all the way to the ned of the wizard, and click create at which point I get an error for each node "unable to create IsilonSD virtual machine Error com.vmware.vim25.InvalidRequest"

As other people have found it's not even talking to the virtual center, no log entries for connections etc. and the log on the managment server is full of Jsva stack traces.

I tried to manually deploy the OneFS node ova, to find that it doesn't deploy due to an issue with VirtualSCSI adapters. I fixed this by editing the ovf file and changing these to be lsilogic . This allows me to manually deploy the ova in virtual center, but even if I re-upload it as a new image to the management server and attempt to create a cluster with the modified image I get the same errors.

Has anyone got this working on vSphere 6.7 ?  One though it have is that in my lab environment the only suitable datastores for creating the nodes on are iSCSI backed of to a compellent, as all my other datastores are NFS mounts.  I wonder if this is the issue (I presume it really wants to deploy to DAS)