Cc 2014 - Nothing shows in inport window when importing AE comp.

Question

So I'm trying to import a comp and there's nothing at all in the window

Answer 1

We found what the culprits were, but I don't know why they'd cause these error messages.
To recap, I have a piece of HD video that I've duplicated 39 times with a different triangular mask on each layer to re-create the whole frame (moving the anchor points of each layer as needed).  The idea is that I then rotate those layers in 3D somewhat randomly, revealing a different video clip on the back side.  To create the "B-side" video for the back sides I duplicated the original 39 faceted layers and parented each to its corresponding "A-side" piece.   I created some opacity expressions to make the A-sides disappear halfway through their rotation with the B-sides appearing at the same point.
My plan was to vary the mask shapes on the A-sides to create variations on the transitions, so I enabled an expression on the masks and pick-whipped the mask shapes on the B-sides to their A-side counterparts.  That seems to be the problem.  Here's the expression (applied to layer 26B):
thisComp.layer("26").mask("Mask 1").maskPath
I repeated this for all 39 B-side layers.  Then I duplicated that comp and inserted new video into the transition.  At some point some part of the software decided some layers were missing or something, creating the above error messages.  The comps still worked as designed; it was just error messages that I had to repeatedly dismiss.  Once I deleted all of these mask expressions the error messages stopped.
Before deleting those expressions we tried renaming the layers (1-39) so they were unique within each comp (Train1, Rail1, etc) but that didn't work.
Feels like a bug.
Shawn Marshall
Marshall Arts Motion Graphics