I'm in North America.

I was going to take advantage of the flash sale, picked out 10 games before it told me I couldn't add anymore to my cart.  Ok fine.  I went in and instead of making a straight up purchase of the 10 games I tried adding funds to my wallet as there where about 30 games I was going to buy while they were dirt cheap.  No go.  I tried with my card and my paypal account and it keeps showing error occurred.  It eventually emptied my cart and keeps randomly kicking me out of the store.  I don't use the store very often, is this common? Is it a volume problem with everyone else trying to access the store? Anyone else having a problem?

Try using the store website

https://store.playstation.com/#!/en-us/home/games

I experienced a little weirdness with the flash sale, too. When I used a PSN card I also got the message that an error had occurred, although in my case it still added the funds to my account. Then I bought the games, but they weren't showing up in my download list on the webstore nor did it show that I had ever purchased them. It wouldn't let me add them to my cart again, either, and said something like, "You are not allowed to download or purchase this content." So I was just about to contact customer support, but when I checked the store on my Vita all my games were there!

So, I don't know. PSN is strange.

Good call.  Much quicker.  Problem was with my card, it's been replaced once (i.e. expired so the number stayed the same but exp date and security code have changed) and I hadn't added funds to my wallet since then.  Like I said I don't use the store very often. Very good call, thank you.

I've always had a problem with it, whenever I play a game and try to get into the store it wont load and the only way to get into it is to restart the ps4 very annoying