My phone's play store has messed up! HELP!

[Jack Hwang]

Remember this old google play? (screenshot 1 - uploaded)
well. i had the newer one since it came out and I turned the phone off for the movies
and turned it back on. It took like 8-10 minutes to turn on and now all the device apps are changed
back to the old version. I cant download or update ANYTHING and it come up like this. (screenshot 2 - uploaded)
Can someone help me?

 

[Golfdriver97]

I am curious if the ROM crashed, since it took so long to boot up. Do you still have all you files?

 

[Jack Hwang]

all my files are there excpet my contacts.

 

[Golfdriver97]

Not sure what to suggest, honestly.

From a Liquid Nexus 5

 

[Jack Hwang]

wait i just found out it has something to do with my samsung account and it isnt valid.
Apparently.
so.... I'm now searching on a solution to that.
It'd be great if you can reply with a solution yourself.