This problem is not solved yet :/ It's doing it for me too on 10.12.1, and I have cornered the bug to Nvidia's latest driver WebDriver-367.15.10.15f01.
Here is the error messages shown in console:
1) Library Validation failed: Rejecting '/System/Library/Extensions/GeForceGLDriverWeb.bundle/Contents/MacOS/GeForceGLD riverWeb' (Team ID: 6KR3T733EC, platform: no) for process 'iBooks(596)' (Team ID: none, platform: yes), reason: mapping process is a platform binary, but mapped file is not
2) Library Validation failed: Rejecting '/System/Library/Extensions/GeForceMTLDriverWeb.bundle/Contents/MacOS/GeForceMT LDriverWeb' (Team ID: 6KR3T733EC, platform: no) for process 'iBooks(596)' (Team ID: none, platform: yes), reason: mapping process is a platform binary, but mapped file is not
3) Error loading /System/Library/Extensions/GeForceMTLDriverWeb.bundle/Contents/MacOS/GeForceMTL DriverWeb: dlopen(/System/Library/Extensions/GeForceMTLDriverWeb.bundle/Contents/MacOS/GeF orceMTLDriverWeb, 265): no suitable image found. Did find:
/System/Library/Extensions/GeForceMTLDriverWeb.bundle/Contents/MacOS/GeForceMTLD riverWeb: code signature in (/System/Library/Extensions/GeForceMTLDriverWeb.bundle/Contents/MacOS/GeForceMT LDriverWeb) not valid for use in process using Library Validation: mapping process is a platform binary, but mapped file is not
4) Unable to create basic Accelerated OpenGL renderer.
Apple, maybe you could assist NVIDIA with solving in bug faster.
Thanks