My wifi don't switch on topic

Hello,

At first...Please forgive my bad english.

I tried CM 12 nightlies in my galaxy s4 mini (gt-i9190), and now i want to return to the stock rom, all things are OK, but wifi don't work (the wifi button become grey, and that's all)

i tried to desactivate wifi power safe mode, but the same thing happens.

Please, help me, i'm blocked now, and i don't know where is the probléme.

Thank you all.