Number range error message coming when creating AO

Hi Experts,

While creating the Architectural object, I am getting error message: Number assignment not defined on top level of hierarchy REBDAO047. However, I have already done the configuration and not able to identify the issue.

Scenario is:

I have a building in which 5 floors defined. Now I have configured the Elevators as AO directly under the Building. During creation on Elevators , I am getting this error.

Can anyone help me to sort out this problem? I would really appreciate your help.

Thanks

Arun