Create LAG withouth setting IP interface
XG forces you to set an IP (v4|v6) interface when you create a LAG. This is OK if you plan to use just the LAG without VLANs or with an untagged VLAN.
BUT, if you don't use untagged VLAN and only tagged ones, you just have to configure some unused IP subnets just to please the web configurator.
XG should may be warn but allow you to configure a LAG without setting the IP interface
Mohammed Elglaind commented
Needed in certain installation.