I am hoping someone out there has experienced this and/or knows how to correct this problem.
No specifics but some questions...
What color space do you have set for your external editing preferences? What bit depth? What format? What compression?
Have you looked at the file that Silver Efex saved in Photoshop (or another color managed app)? When you open it, what color space is embedded in the file?
When you look at the image in LR's Develop module, what does the image history look like? Is there any stray history steps?
When you look in the Metadata menu, at the bottom, is the Save or Read Metadata from File grayed out? Or is there an option to Read the metadata (which means LR thinks there is a metadata mismatch between what's in the file vs what's in the LR database).
BTW, Nik support's discussion of display profiles it totally bogus and ignorant...there is no way that the display profile can alter the viability of an image. It may alter how the image is displayed, but as long as the profile is not hosed and it's tagged as a Display class profile, that should have zero bearing on the image. And there would be no difference between Library & Display since LR is using the same profile in each case.
The only thing you haven't mentioned is how you are calibrating the display and what hardware/software you are using.