Error: illegal usage link in project

Hi pros,

WC 9.1 m050 and proe wf4 m190

I am getting error: "Illegal usage link creation. "Part - XXXX-XXXX-XX, -.8 (Design)" is in a Project and can not use "Part - 3585-06CN138" because it is in a PDM context that is not PDM checked out or shared to the same Project." Whole library family table where3585-06CN138 is an instance is definetely shared to the project. What gives?

Help will be greatly appreciated!

D