Error: Inheritance security rules violated by type ItemsCollectionEditor in C#

using System.Reflection;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
using System.Security;
 
// General Information about an assembly is controlled through the following 
// set of attributes. Change these attribute values to modify the information
// associated with an assembly.
[assembly: AssemblyTitle("WindowsFormsControlLibrary2")]
[assembly: AssemblyDescription("")]
[assembly: AssemblyConfiguration("")]
[assembly: AssemblyCompany("SSSSSSSSS")]
[assembly: AssemblyProduct("WindowsFormsControlLibrary2")]
[assembly: AssemblyCopyright("Copyright © SSSSSSSSS 2012")]
[assembly: AssemblyTrademark("")]
[assembly: AssemblyCulture("")]
 
// Setting ComVisible to false makes the types in this assembly not visible 
// to COM components.  If you need to access a type in this assembly from 
// COM, set the ComVisible attribute to true on that type.
[assembly: ComVisible(false)]
 
// The following GUID is for the ID of the typelib if this project is exposed to COM
[assembly: Guid("ed5d434c-36e8-4883-a4d3-3eb6459546b3")]
 
// Version information for an assembly consists of the following four values:
//
//      Major Version
//      Minor Version 
//      Build Number
//      Revision
//
// You can specify all the values or you can default the Build and Revision Numbers 
// by using the '*' as shown below:
// [assembly: AssemblyVersion("1.0.*")]
[assembly: AssemblyVersion("1.0.0.0")]
[assembly: AssemblyFileVersion("1.0.0.0")]
 
//[assembly: AssemblyDelaySign(true)]
[assembly: AssemblyKeyFile("Saino.snk")]
[assembly: AssemblyKeyName("")]
[assembly: System.Security.AllowPartiallyTrustedCallers]
 
[assembly: SecurityRules(SecurityRuleSet.Level2, SkipVerificationInFullTrust = true)]
//[assembly: SecurityRules(SecurityRuleSet.Level1)]