So I've had this problem with the new LG G3 that came out basically when i launch a Google service like YouTube, Google play etc. it has the search bar and under that is a white screen with the loading circle. Nothing happens after that. I've basically tried everything. Nothing but resetting the phone has worked and even after that my problem came back after 2 days. If anyone can help with this it would be much appreciated.
If you're still having problems, I'd RMA it if possible. I've heard a lot of bad things about the G3, from reviews and friends.
I would RMA it if possible, sounds like something is wrong with the OS or apps.
If RMA isn't possible; Connect to a desktop and hop into the FS. Android is verbose in log files and .ini like files. Check on those. I haven't dug into the LG G3 FS yet but see if you can find the "com.google.googleservices" folder and mine the info files. You might find the exact error you are experiencing. Let me know what you find!