Opening a file from Vis Mock-up in TcEngineering

Hi,

What is the reason that sometimes I can't use the "Show In" that led to "My Teamcenter" (please, see the highlighted text in the pictures below, "My Teamcenter" it is inactive):



......and sometimes "My Teamcenter is active (and can open the file from Vis Mock-up in TcEngineering)?



How could I always make "My Teamcenter" option active?

Thanks!



CAD 2015