Unable to update after rooting and unrooting! What do I do?

[AC Question]

Unable to update after rooting and unrooting!

I have a Infocus M260 which runs Android 5.0.2 lollipop. I rooted it using the kingroot app and I unrooted it with the same app. I also factory reset my phone. I got a 311mb update, I downloaded it and it starts to install(with the android bot pic) and after some time I get an error message.