I am yet to open a support case for this but after upgrading to vSphere 6.5 U1 with NSX 6.3.2 I am unable to create a new logical router interface.
After entering the information and pressing “OK” I received a blank error as seen below.
If you are in a pinch and need to get the interface set up ASAP and you have Powershell and PowerNSX installed then go ahead and replace your values in the script lines below and run that. It should successfully create the new interface even though the GUI has the blank error.
Connect-NSXServer $logicalswitch = Get-NsxLogicalSwitch -name LogicalSwitch1 Get-NsxLogicalRouter NSX-DLR | New-NsxLogicalRouterInterface -Name LogicalSwitch1 -Type Internal -ConnectedTo $logicalswitch -PrimaryAddress 192.168.180.254 -SubnetPrefixLength 24 -MTU 1500