Copying assembly from 'Temp/Assembly-CSharp-Editor.dll' to 'Library/ScriptAssemblies/Assembly-CSharp-Editor.dll' failed code example

Example: Copying assembly from 'Temp/Assembly-CSharp-Editor.dll' to 'Library/ScriptAssemblies/Assembly-CSharp-Editor.dll' failed

//Try  : 
//Reimporting a script
//Restarting unity