Unable to Activate Windows Store App

For me a RESTART of pc solved this error message.

I ran into the same issue, and tried rebuilding, cleaning, deleting temp files, rebooting the computer, etc... and nothing helped.

Then finally I made a release build then went back to debug. And now it works.

I have no idea what happened, nor if that really helped, but it's worth a try.

This happened to me once too, but the deleting build directories advice fixed it. Specifically, you just need to delete the bin\Debug and bld\Debug folders in your projects. Their contents will be regenerated by Visual Studio when you rebuild. I assume that this is only one project since it's a Hello World app; otherwise I would ask if you deleted build directories from all projects in your solution.

You can also try running "Clean Solution" from the BUILD menu in Visual Studio.

I'm sorry...it's horrible if this is happening on a clean install as you describe.