Path for linked rig missing

Hello Friends,

We are working on a project where the character rigs are linked into a scene before we start animating.

Our problem is: in one of the scenes i get an error message when i try to open the scene - we get an error "unable to open 'd:\Dropbox…

Other scenes are working though. Just this one is not.

In my prefrences i have relative paths turned on.

Any ideas?

Thanks a lot