U5.6 + Asset Errors

help, How to fix all these errors?
I've deleted:

• BEP3
• Medieval Environment
• ProGrids
• Underworld

and Re-import with same errors.
example: UnityStandardAssets was imported from asset store, so why would it be "missing"?

1. Assets/BEP3/BEP_3_Standard Assets/Image Effects (Pro Only)/EdgeDetectEffect.cs(7,33): error CS0246: The type or namespace name `ImageEffectBase' could not be found. Are you missing `UnityStandardAssets.ImageEffects' using directive?
   
   
2. Assets/Medieval Environment/Shaders/Desaturate/DesaturateEffect.cs(5,33): error CS0246: The type or namespace name `ImageEffectBase' could not be found. Are you missing `UnityStandardAssets.ImageEffects' using directive?
   
   
3. System.IO.FileNotFoundException: Could not load file or assembly 'Assembly-CSharp-Editor' or one of its dependencies. The system cannot find the file specified.File name: 'Assembly-CSharp-Editor'at System.AppDomain.Load (System.String assemblyString, System.Security.Policy.Evidence assemblySecurity, Boolean refonly) [0x00037] in /Users/builduser/buildslave/mono/build/mcs/class/corlib/System/AppDomain.cs:746 at System.AppDomain.Load (System.String assemblyString) [0x00000] in /Users/builduser/buildslave/mono/build/mcs/class/corlib/System/AppDomain.cs:728 at (wrapper remoting-invoke-with-check) System.AppDomain:Load (string) at System.Reflection.Assembly.Load (System.String assemblyString) [0x00000] in /Users/builduser/buildslave/mono/build/mcs/class/corlib/System.Reflection/Assembly.cs:576 ProBuilder2.EditorCommon.pb_ProGrids_Interface.GetProGridsType () [0x00000] in <filename unknown>:0 at ProBuilder2.EditorCommon.pb_ProGrids_Interface..cctor () [0x00000] in <filename unknown>:0
   
   
4. UnityEditor.EditorAssembliesrocessInitializeOnLoadAttributes()
   
   
5. Assets/Underworld/Origin/Tools/Image Based/DesaturateEffect.cs(5,14): error CS0101: The namespace `global::' already contains a definition for `DesaturateEffect'

 

Paste this, top of your script:
using UnityStandardAssets.ImageEffects;