App store won't update.

Hello,

My second iPad connected to the same Apple id has a problem when trying to use app store for the first time. When opening app store it says:

"The Apple Store app has been uodated. Download the new version on the App Store."

And then button "Update".

After pressing update it opens up Safari and straight away the error message pops up: "Safari cannot open the page because the address is invalid."

Anyone can help me with this matter?