I didn't downgrade, and I made a success I have installed again the play store.
I watched and tried at least 10 times, all the methods i have found. Almost removed all the apps i have installed, The only one that have left is WhatsApp, and i will probably remove it and give a try again.
I have tried ppfix apk,
Fix with rose
and one more tutorial for fixing this error.
Can you make a guess what am i doing wrong with all these methods? (I carefully pause videos and do every step exactly the same...