I have the same issue, only I've been sitting with it since 25 Nov :( Sad panda.
- No LoL splash, just a white rectangle
- The grey bar under the dock icon loads fully, the icon disappears then reappears, bounces three times and disappears for good.
- And....nothing.
I've followed all of the steps on the Patching Issues help page, and most of the ones on the Connection Issues page multiple times on two machines, as well as a number of other potential fixes that worked for other people, but nothing has worked so far.
I can get the game patched, started and logged in on safe mode, but haven't tried playing, because even if it does work (which I doubt, as the screen flashes every time anything refreshes), I'm not keen on playing with no sound indefinitely.
I have been speaking (and sending all sorts of logs and reports) to one of the support staff since 27 November, but he eventually told me that he is certain it is a network issue. However, I have tried patching on two different networks since (including one on which a friend was busy playing LoL), and had the exact same result as above.
Please, for the love of all things sacred, can someone help a brother out. This is frustrating the life out of me.
Great big tears.
A massively frustrated guy.