Default or so stopped working

So I have now a really strange problem... I'm also not a noon or something else I really know much about android and especially HTC one m8 etc...the problem is I had really done all things to fix that...

But somehow without Doing anything I rebooted and or so stopped working, gplay updates aren't working anymore also I can't install there any new app...already tried to delete data/cache for several Google things etc but nothing working...I hope someone finds a solution as I really don't have time to make a factory reset -.-

Gesendet von meinem HTC One_M8 mit Tapatalk
Its simple read before asking and use the search button and always be thankful its FREE!!!

Devices : HTC HD2 (Sold/broken), HTC One X (has my sister now), HTC One M8 (current) (changing roms always after few weeks of use and testing)