ETS 5.7.3 - IP backbone connectivity

While setting up and adding devices in to project, encountering an issue.  

Backbone is selected as IP.----- IP router (HDL M/IPRT) is installed as 1.0.0, then while installing 

the line coupler (Gira 1023) as 1.1.0, message appear that 

not allowed on a backbone line with IP.  In ETS 4 the same structure works perfectly.  

can someone comment on it with a possible solution.  Regards