Weird interaction between ctrl+z and structuration relation

[BernardoFBBraga]

Model is correct when creating the relation the first time, is incorrect after ctrl+z and recreating relation

Steps to recreate bug: 1- create Nominal Quality 2- create Decimal Ordinal Dimension 3- create structuration relation between them 4-check model (no errors) 5-Ctrl+z (structuration relation is now gone) 6- create structuration relation again 7- check model (error appears "All Reference Structures of a Nominal Quality should be Nominal Reference....)