Well, things started working here for no reason, but I get the feeling that I got lucky. I'm waiting for a logical solution as well.
EDIT: There you go. Same error here. I can not access the list of my apps again.
I have this exact same problem. In fact, I have many problems. Tell me, can you access the list of apps you own in the Windows Store?
I have also tried everything you said in the main post in vain.
EDIT:
Well, what do you know? I just spammed try again on an App and now everything works.