Desperate Ota not installing after unrooting phone please help

Hey guys I am a semi noob
I rooted my phone installed cm12.1 and changed a few kernels installed xposed and decided to get stock otas so reverted all this
Flashed stock recovery and ROM
And locked my boot loader
But it is still unable to install updates I just don't get
Please help (I did uninstall closed)
Super su says binary not installed


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