Unity Building "failed": UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr)

Question

Basically I am building my project in random locations and the project folder and nothing is working so I was wondering if it was something else. I am getting these errors:

Error 1: Error building Player: DirectoryNotFoundException: Directory '/Shaders/Water' not found.

Error 2: Build completed with a result of 'Failed'
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr)

Error 3: UnityEditor.BuildPlayerWindow+BuildMethodException: 2 errors
  at UnityEditor.BuildPlayerWindow+DefaultBuildMethods.BuildPlayer (BuildPlayerOptions options) [0x0020e] in C:\buildslave\unity\build\Editor\Mono\BuildPlayerWindowBuildMethods.cs:181 
  at UnityEditor.BuildPlayerWindow.CallBuildMethods (Boolean askForBuildLocation, BuildOptions defaultBuildOptions) [0x00065] in C:\buildslave\unity\build\Editor\Mono\BuildPlayerWindowBuildMethods.cs:88 
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr)

Error 4: DirectoryNotFoundException: Directory '/Shaders/Water' not found.
System.IO.Directory.GetFileSystemEntries (System.String path, System.String searchPattern, FileAttributes mask, FileAttributes attrs) (at /Users/builduser/buildslave/mono/build/mcs/class/corlib/System.IO/Directory.cs:514)
System.IO.Directory.GetFiles (System.String path, System.String searchPattern) (at /Users/builduser/buildslave/mono/build/mcs/class/corlib/System.IO/Directory.cs:308)
System.IO.Directory.GetFiles (System.String path) (at /Users/builduser/buildslave/mono/build/mcs/class/corlib/System.IO/Directory.cs:303)
UltimateWater.Editors.EditorShaderCollectionBuilder.CleanUpUnusedShaders () (at Assets/Ultimate Water System v1.0.0/Scripts/Editor/EditorShaderCollectionBuilder.cs:54)
UltimateWater.Editors.WaterShadersCleanupTask.OnWillSaveAssets (System.String[] paths) (at Assets/Ultimate Water System v1.0.0/Scripts/Editor/EditorShaderCollectionBuilder.cs:140)
System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) (at /Users/builduser/buildslave/mono/build/mcs/class/corlib/System.Reflection/MonoMethod.cs:222)
Rethrow as TargetInvocationException: Exception has been thrown by the target of an invocation.
System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) (at /Users/builduser/buildslave/mono/build/mcs/class/corlib/System.Reflection/MonoMethod.cs:232)
System.Reflection.MethodBase.Invoke (System.Object obj, System.Object[] parameters) (at /Users/builduser/buildslave/mono/build/mcs/class/corlib/System.Reflection/MethodBase.cs:115)
UnityEditor.AssetModificationProcessorInternal.OnWillSaveAssets (System.String[] assets, System.String[]& assetsThatShouldBeSaved, System.String[]& assetsThatShouldBeReverted, Int32 explicitlySaveAsset) (at C:/buildslave/unity/build/Editor/Mono/AssetModificationProcessor.cs:147)
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr)

The project isn't building.

Answer 1

I had a similar problem but not exactly this. You can try to change the API compatibility level under Project Settings > Player.

While searching for the solution, I found that people were switching to.Net2, but mine was .Net2 by default, so I switched to .Net 4.x and it builds successfully.