I'm not sure what's going on exactly but my store keeps cutting in and out and more often than not, I'm not able to actually get into it. I was able to buy my RP but after that, I couldn't get in again :/. Send help Riot!
Yes, I am also having a problem. The main page will show, but if I try to access anything, it then shows an error message. If I had to guess, reading through various bug reports and what have you, the odds are that it is our fault somehow and we will be told to reinstall the client. Maybe not, but probably. In fact, here is what it says: Session Expired
An error is preventing your store request from being processed at this time. This issue can typically be resolved by closing and relogging into the League of Legends client. We apologize for the inconvenience, and thank you for your patience.
If this problem persists, please contact us at support.riotgames.com
