Something's Going on with my Client. (Not patcher)

I open up the client and log in, but sometimes it doesn't let me, and other times it does. Not sure if this is my internet, or something else, but that's not the biggest problem. The other part of this is that whenever i open up the shop, the session either expires, and does not refresh, or it seems to open just fine. If the shop opens properly, it seems to be nothing. But, when i click on any of the tabs, the area where the content would be goes blank, save for a small grey rectangle at the top, in the middle. Any help is greatly appreciated!