Unable to change maturity of a Part in Different Collaboration Space

Hi All,

I am using 3DEXPERIENCE 2016x.I have a common part(Part1) in two collaboration space(Common Space and External Component).Common Space has a Private Visibility where as External Component has public Visibility.I logged in to Common Space Collaboration Space as Author role and search for the Part1 and try to change its maturity to "To Freeze" from "In Work".but its throwing error as "You do not have necessary previledges to do this".

Can anybody help me on this , Is this a designed behavior or a Problem ?

Thanks

Rajesh