I just fixed this issue for myself and hopefully this could help you out.
I couldn't get my keyboard shortcuts window to open up for the past two days. I just ordered a new iMac and had been able to open Keyboard Shortcuts when I was logged in under my associates adobe id (we first installed creative cloud using his account). After I logged out and back in under my own creative cloud account it wouldn't display the keyboard window at all and I couldn't sync my preferences. I would click on the menu Premiere Pro CC > Keyboard Shortcuts and nothing would happen, it wouldn't open a new dialog window at all no matter how many times I tried. I even tried the option+command+K shortcut and nothing opened.
I signed out and back in multiple times and restarted. I was going to reinstall Premiere next but then I finally tried the Sync Settings option on the Premiere splash screen (see image) and that finally synced everything. My keyboard shortcuts window would open when I clicked on the menu option and I could select my preferred keyboard layout.
Hope this helps? Not sure if it will...
