I am using Creo Parametric Release 4.0 and DatecodeM150
Creo 4.0 circular references in assembly has components in a "Null" status and cannot remove them to correct the circular references
Here are the errors that I faced
Feature number 235 (COMPONENT, id = 1536836) is not in the model tree and its classified as a Null component
Feature number 235 (COMPONENT, id = 1536836)
in model 936009 refers to:
Feature number 339 (COMPONENT, id = 1535409)
in model 936009 must follow after:
Feature number 235 (COMPONENT, id = 1536836)
in model 936009 - circle closed.