There is a custom button on one of your toolbars(maybe created by your CAD Coordinator?)which tries to open a dll in your session.
NX is not able to open this dll. It either can't find it or it is not signed for your NX version. If you follow the instruction in your error message you can find out which dll is causing the problem.
Ronald van den Broek
Senior Application Engineer
Winterthur Gas & Diesel Ltd
NX9 / TC10.1.2
Building new PLM environment from Scratch using NX12 / TC11