When you launch PSO2, you can probably check task manager and find a service called wsappx forever looping and never actually doing anything but eating your CPU. Well I have a solution to that, basically what happened is that Windows Store is trying to start itself even though it already on. Two things I did that helped.

Start by running the Windows Store Apps troubleshooter.

Open Start > Settings > Update & security > Troubleshoot

Scroll down to the bottom

Click Windows Store Apps

Click Run the troubleshooter

When complete try opening the Store again.

Also check if the Store works in another user account.

Press Windows key + R

Type: wsreset.exe

Hit Enter

Do this a couple times then try launching the Store again.

This all worked for me, hopefully it helps you. I'm gonna go make a sandwich now, gl!

You do not have to run wsreset.exe more than once. Also, should preferably be run as administrator (it does not default to this, even if you're account is an administrator). And you don't have to hit Windows + R to run anything anymore, just hit the Windows key and start typing, this will give you more options up front (such as being able to run as admin without any hidden keyboard shortcuts).

I started getting the wsappx hang today. These steps aren't solving it.