Hello!
Have the same issue with preload screen.
Here is my configuration:
OS X 10.10.1 (14B25)
Model Name: iMac
Model Identifier: iMac14,2
Processor Name: Intel Core i5
Processor Speed: 3,2 ГГц
Memory: 8 GB
NVIDIA GeForce GT 755M
Have to use bootcamp :(
