Problems Building

Hi, I´m having little issue while compiling my game. I do not know what is happening or what to do, can anyone help me ?

The error two up refers to a problem in build settings. Maybe that is a starting point.

This thread from Unity Answers seems to deal with this type of problem
https://answers.unity.com/questions/1574025/build-fail-unity-201830b9.html

THANKS!!! I deleted the .sln file created by VS as shown in the thread and worked just fine!!