When attempting to take a backup from a production HA Pair and restore it to a Standalone test appliance, You receive the following error;
“This appliance should not be restored while in replication mode”.
There may be an issue with the appliance that is causing it to believe it's in a different mode. Under normal circumstances it should be possible to complete this restore, as long as your production and test appliances are running the same version.
One possible solution would be to apply the "Make_Standalone" patch to your test appliance. This should reset the mode and allow you to restore the backup. Contact Support if you do not currently have access to this patch.