LolClient: LolClient.exe - Application Error

"The instruction at 0x77dc32b0 referenced memory at 0x063c5fda. The memory could not be read. Click on OK to terminate the program."

What is this and I was just play LoL a couple of hours ago, not even a couple of hours, go to log back in and get this error, any fixes, anyone know whats up?

It happens when I click Launch on the client.