Problem in ota-update after installing kingroot

Hi all ,

This problem is facing very one how install kingroot and made his/her device rooted with kingroot , the root is done will , but after Root we can receive ota updates but when we download and install the ota update a problem found :

Unexpected error : install-recovary.sh status 7

I have trying to make full un-root by kingroot , or superus and nothing fixed until now !!!

Some people told me that you must install stock-rom !?
But why stock-rom if there is better and easy solution ?

I need your help developers I guess this problem not hard one for you ^_^ .

So who is the hero that's will save the day :(

Thanks.