I cannot get my project to build for PC

This is what happens after I try to build, Please help!


Console:

UnityEditor.BuildPlayerWindow+BuildMethodException: 3 errors
at UnityEditor.BuildPlayerWindow+DefaultBuildMethods.BuildPlayer (BuildPlayerOptions options) [0x0021f] in C:\buildslave\unity\build\Editor\Mono\BuildPlayerWindowBuildMethods.cs:182
at UnityEditor.BuildPlayerWindow.CallBuildMethods (Boolean askForBuildLocation, BuildOptions defaultBuildOptions) [0x00065] in C:\buildslave\unity\build\Editor\Mono\BuildPlayerWindowBuildMethods.cs:89
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr)

Look at the 1st error:
The assembly UnityEditor cannot exist in build.

Any of your script have using UnityEditor; will make the build failed.
Remove it or change it to

#if UNITYEDITOR
using UnityEditor;
#endif