Oh dear... please help.
I can't see the mini previews of my items in the inventory and even when i click i can not equip them. this is same both on my main and my mule account. please help... my avi is nekki-nekki

First things to check:

Is your browser up to date?

If so, did you try a different browser?

If so, did you try a different computer or device?

If so... Something is borked in the code which we are working diligently on trying to fix! I'll add your name to the list of users that are having troubles!

I had this same issue and once had to update to get it to work, and a second time had to clear cookies to get it to work.
Also sometimes just closing down your browser and all open windows and reopening it if you've left it open for to long will do the trick.