OPIM SS6 - Unable to create Iso sheet splitting option on attribute

I'm trying to use split sheet option based on attribute with the help of this guide

https://communities.bentley.com/products/plant/w/plant_design_and_engineering__wiki/29903/how-to-use-various-iso-sheet-splitting-options-in-openplant-isometrics-manager

I've create an new Relationship named SHEET_NO

Image may be NSFW.
Clik here to view.

Checked the option to split on attribute SHEET_NO

Image may be NSFW.
Clik here to view.

I'm getting an error on ISO creation with OPIM, so what am I doing wrong?

Image may be NSFW.
Clik here to view.

Regards,

Sebastien