I've recently run into the same problem a number of other user have. When using the pipe routing add in you try to drag in a component like a flange from the design library and the dreaded "Drag and Drop has Failed" dialog box pops up. I understand WHY this is happening. The assembly I'm working on was once on another user's laptop and he did a pack and go to get it all on the network.
BUT, here's the real problem. It's happening with other assemblies as well. I try to run through the tutorial files and the same thing happens.
Now I know the solution is to rename the design library parts. But are you renaming them in the assembly? Or are you actually renaming the files? I tried renaming the instances in the assembly and it tells me that I cannot rename Design Center Parts.