There is an issue with RAW format files in last 2 releases of web drivers. Symptoms include:
- RAW photos appear as solid yellow squares in Aperture view area
- RAW photos take a very long time to open in finder or Preview.app
There is some further info in:
http://forum.netkas.org/index.php?action=printpage;topic=11137.0 (search for the word "yellow")
This bug has apparently been reported to Nvidia by several people. Hopefully will be fixed in subsequent release.
In the meantime, only option seems to be to roll back to 346.03.01b07, which means rolling back to El Capitan 10.11 (01b07 will not install on 10.11.1).