Launch Failed! Unknown Error

Hello,

I’m trying to build my game so I can add it to the google play store for Alpha testing but I can’t get it to build as I have this error pop up.
I’m building for Andriod.

More errors if this helps

Problem Solved!

Was down to the SDK being broke somewhere so I reinstalled it and works fine!

can u please say me how to fix that thing more clearly I really need it