That's happening because the part has external references to another assembly.
I made the blue secected part out of a library component.
Where can I look up references and delete them to solve the problem?
I want to reference some other parts to this blue part and Solidworks won't let me.
Is it possible to break only one reference from the list, not all of them?
Thank you very much.
How do I solve this problem?
Is there any way to quickly cut off all external references to eliminate problems?
It is a small bug in Solidworks. I worked around it by disabling external references under options>document properties>external references.
Than i played around with the assembly and enabled this again.