sorry, we were unable to complete your purchase. Maybe check your internet connection?

Try performing a hard reset EXACTLY like this. Hold the power button on the console for 8 seconds or until the power shuts down completely.
Unplug the power cord from the back of the console for 5 minutes.
Plug the power cord back in and restart the console.

Hi there,

Sorry to hear you are having this problem.

Are you having this issue on Xbox or PC? Have you tried hard resetting your console?

If you haven't here is how:

(Hold the power button on the console for 8 seconds or until the power shuts down completely. Unplug the power cord from the back of the console for 5 minutes. Plug the power cord back in and restart
the console.)

I hope this helps.

I have the exact same problem with Minecraft for windows 10. When trying to buy a Realms subscription, I get that exact same error. I have been able to buy anything else from the minecraft store without issue.

Hello,

I would try making purchase from the app,laptop,computer,smartphone. Or any device that has internet and the access to a browser.

Could it be some momentary problem, or does it occur frequently? Clear the cache and try again.