Build Problems Please help

I’m trying to build my PC app
This what I get:

ArgumentException: The Assembly Mono.WebBrowser is referenced by System.Windows.Forms (‘Assets/StandaloneFileBrowser/Plugins/System.Windows.Forms.dll’). But the dll is not allowed to be included or could not be found.
UnityEditor.AssemblyHelper.AddReferencedAssembliesRecurse (System.String assemblyPath, System.Collections.Generic.List1[T] alreadyFoundAssemblies, System.String[] allAssemblyPaths, System.String[] foldersToSearch, System.Collections.Generic.Dictionary2[TKey,TValue] cache, >UnityEditor.BuildTarget target) (at C:/buildslave/unity/build/Editor/Mono/AssemblyHelper.cs:150)
UnityEditor.AssemblyHelper.AddReferencedAssembliesRecurse (System.String assemblyPath, System.Collections.Generic.List1[T] alreadyFoundAssemblies, System.String[] allAssemblyPaths, System.String[] foldersToSearch, System.Collections.Generic.Dictionary2[TKey,TValue] cache, >UnityEditor.BuildTarget target) (at C:/buildslave/unity/build/Editor/Mono/AssemblyHelper.cs:156)
UnityEditor.AssemblyHelper.FindAssembliesReferencedBy (System.String paths, System.String foldersToSearch, UnityEditor.BuildTarget target) (at C:/buildslave/unity/build/Editor/Mono/AssemblyHelper.cs:190)
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr)


And this


UnityEditor.BuildPlayerWindow+BuildMethodException: 3 errors
at UnityEditor.BuildPlayerWindow+DefaultBuildMethods.BuildPlayer (UnityEditor.BuildPlayerOptions options) [0x00234] in C:\buildslave\unity\build\Editor\Mono\BuildPlayerWindowBuildMethods.cs:190
at UnityEditor.BuildPlayerWindow.CallBuildMethods (System.Boolean askForBuildLocation, UnityEditor.BuildOptions defaultBuildOptions) [0x0007f] in C:\buildslave\unity\build\Editor\Mono\BuildPlayerWindowBuildMethods.cs:96
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr)


What does it mean?

This solve my problem
here

Problem is not solved there !!! At least not for everybody. That solution just says you should change your api compatibility to .NET 2.0, but it doesnt work for everybody. You shoul look at this reddit post . My problem was, that i did not include .dll file for every platform. Or just some of .dll s where not included. Try to do that and than solve your other problems. I lost almost hour on this problem, so i hope somebody finds it helpful.

Just wanted to post how I solved this because neither of the solutions given helped and this is the first page that comes up when googling my problem. First I had some errors because I had an assembly reference in my Assets/Editor folder and had to set the “platforms” option to only editor. That solved the initial errors, but I was then unable to find the Mono.WebBrowser assembly reference. To solve that I had to change from .Net 2.0 to .Net 4.x in player settings.

Hope that helps someone in the future.