I am using Photoshop CS6 v 13.0.1 x64. I have been using Photoshop for years, of course various versions. All updates have been installed. My OS is Windows 7 Pro X64 with all applicable updates. I just downloaded NEF files from my D2X and was opening them in Camera Raw. I then selected similar NEFs and clicked Synchronmize but nothing happened. No error message, nothing! This never happened before. I have 24 G RAM, plenty of free space on the C drive (334Gs). I.have the OnOne plug in installed and may have added some free presets lately.
I used to download pix from my cameras and never encountered this problem before.
No changes were made to the system that I am aware of.