"Unable to Purchase" App Store Error

I usually get it when I decline to buy something.

 

I've had that, and still do... The workaround I found was to try to download it, get the error, then completely close the app store (through multitasking), and try again. It usually works the second time (it gives another error about having already purchased it (even when it was free) but does download)

 

I got this for few days, even if I wanted to update the apps (iPhone 5S, iOS 7.0.3). Non of the tricks suggested here did work. Had enough and did manufacture reset through iTunes. It did fix the problem.

 

I've been running into this since the GM. Seems to happen once or twice a week and then go away. The only thing that works for me is to buy the app through iTunes and then download it on my iPhone/iPad. Called Apple about it a few times and they said the issue is on their end. They've always been able fix the issue (temporarily) but won't offer any explanation as to why it's happening. I usually just wait it out now... It tends to eventually go away on it's own and a call to support ends up taking 30-40 minutes of my time.

 

Delete your keyboards, download app, re add keyboards

This is really annoying, and I don't know how or why this fixes the issue but at least you can do it all from your idevice.

Go to your settings and remove all your keyboards.

Quit out of app store and settings through multitasking.

Try to download the app again, it should work.

Then add your keyboards back.

If it doesn't work, try adding/deleting/adding/deleting extra keyboards a couple times. You might want to switch from English US to English UK.

After some puzzling around with it, you'll get the apps to download and you shouldn't have the problelm again (at least I haven't in a couple weeks).

Good luck