Keep getting "There was an unexpected error with the login session. Please try again." I've already tried the click the x then sign out "solution" and that hasn't worked. I've also reinstalled the game 2 times and that hasn't fixed anything either.
I actually "fixed" this problem by moving the computer across campus back to my dorm and connecting to another network.
I had the same problem, and it appears to be a problem caused by my router DNS setting. Here's how I solved it: 1- Go to your network setting. 2- Select you active network and click on "Properties". 3- Double click on the "Internet Protocol Version 4 (TCP/IPv4)". 4- Change DNS to "Obtain DNS server address automatically". 5- Run lol client, it should run ok now. Hope this works for you .. good luck.
Found out that my network firewall was blocking it. Had to allow the traffic through before I could get the client working again.
