Why is my mac deauthorized after hard crash?

So I'm working along and my computer hard crashes / power off to a restart.

I try to launch an application I purchased from Mac store and get the message that I need to login to authorize etc... even though I've been using this computer all along.

I then try to use an application that also authorizes based on computer and it no longer works. I need to login with my credentials but it says that my app is already being used on another computer so I need to get them to reset my account even though it is the same computer.

My question is, how can a hard crash "reset" my computer authorization/identifier? so that all systems no longer think it is the same computer?