There’s an annoying bug when editing images using the Nik Collection of plug-ins and Aperture 3.5.1 on Mac OS X Mavericks: once you save the image and go back to viewer mode, it only shows grey. At this point you cannot see any other image in the viewer anymore—edited with Nik or not. Yet interestingly, if you open the loupe, you can see the image through it (see screenshot below). After restarting Aperture, everything comes back to normal. However restarting Aperture every time you edit a picture with Nik Plug-ins doesn’t sound like a good plan.

Here is my workaround:

Do NOT start the plug-in from the viewer mode, but rather from the Browser mode (right click on the image: edit with plug-in, then the Nik Plug-in; Silver Effex Pro 2 for example). Once you save the image and you are back into Aperture, then you can enter the Viewer mode without getting the grey screen bug!

It seems that the bug is related to generating the preview after editing with Nik (although forcing to generate a new preview doesn’t fix the problem).

Let us know in the comments if this works for you!

Note: I’m currently running a fresh install of Mavericks on a MacBooK Pro with Retina display, Aperture 3.5.1 and Nik Collection version 1.108