Number Range Supersession

Hello Gurus,

I am trying to create a supersession chain but i am getting the following error "

Internal and External number ranges not defined for group type Supersession Chain"

I then went into SNUM-->/INCMD/GRP-->ranges-->Change Groups

Here I created a Group with name Supersession chain with range 1 to 99999999999999999999 and also assigned elements to the group as shown

But after this also i am still getting the error above . Please find the screenshots below

Am i missing anything

Regards,

Nick