How do you buy guns?! I have 2500 credits and I'm trying to buy the Scrapper (for example) and when the gun is selected it says "BUY 1500 CREDITS" but pressing Space, E, shift, every button I can find does not buy the gun. The "start" stays locked saying access denied. I've mashed every key on my keyboard and nothing will actually buy the gun. Help. :( 
Edit: turns out I can't buy gear either, but I can buy buffs. What's wrong?!