Unhandled Exception: System.UnauthorizedAccessException

Hey guys,

So I have been having this issue for awhile now. Where Unity says the comuter refused permission for it to access the compilers. Here is the error:

 Internal compiler error. See the console log for more information. output was:Assets/Downloaded Assets/CreateScriptDialog/Editor/NewScriptWindow.cs(400,34): warning CS0618: `UnityEditor.EditorGUIUtility.LookLikeControls(float)' is obsolete: `LookLikeControls and LookLikeInspector modes are deprecated. Use EditorGUIUtility.labelWidth and EditorGUIUtility.fieldWidth to control label and field widths.'
 Assets/Downloaded Assets/WorldBuilder/Editor/WorldGen.cs(125,35): warning CS0618: `UnityEditor.EditorGUILayout.ObjectField(string, UnityEngine.Object, System.Type, params UnityEngine.GUILayoutOption[])' is obsolete: `Check the docs for the usage of the new parameter 'allowSceneObjects'.'
 Assets/Photon Unity Networking/Editor/PhotonNetwork/PhotonViewInspector.cs(20,26): warning CS0618: `UnityEditor.EditorGUIUtility.LookLikeInspector()' is obsolete: `LookLikeControls and LookLikeInspector modes are deprecated.'
 Assets/Photon Unity Networking/Editor/PhotonNetwork/ServerSettingsInspector.cs(26,26): warning CS0618: `UnityEditor.EditorGUIUtility.LookLikeInspector()' is obsolete: `LookLikeControls and LookLikeInspector modes are deprecated.'
 
 Unhandled Exception: System.UnauthorizedAccessException: Access to the path "D:\projects\Unity\Heli Duel\Temp\Assembly-CSharp-Editor.dll.mdb" is denied.
 
   at System.IO.FileStream..ctor (System.String path, FileMode mode, FileAccess access, FileShare share, Int32 bufferSize, Boolean anonymous, FileOptions options) [0x00000] in <filename unknown>:0 
 
   at System.IO.FileStream..ctor (System.String path, FileMode mode, FileAccess access, FileShare share, Int32 bufferSize, Boolean isAsync, Boolean anonymous) [0x00000] in <filename unknown>:0 
 
   at System.IO.FileStream..ctor (System.String path, FileMode mode, FileAccess access) [0x00000] in <filename unknown>:0 
 
   at (wrapper remoting-invoke-with-check) System.IO.FileStream:.ctor (string,System.IO.FileMode,System.IO.FileAccess)
 
   at Mono.CompilerServices.SymbolWriter.MonoSymbolWriter.WriteSymbolFile (Guid guid) [0x00000] in <filename unknown>:0 
 
   at Mono.CSharp.SymbolWriter+SymbolWriterImpl.WriteSymbolFile () [0x00000] in <filename unknown>:0 
 
   at Mono.CSharp.SymbolWriter.WriteSymbolFile () [0x00000] in <filename unknown>:0 
 
   at Mono.CSharp.CodeGen.Save (System.String name, Boolean saveDebugInfo, Mono.CSharp.Report Report) [0x00000] in <filename unknown>:0 
 
   at Mono.CSharp.Driver.Compile () [0x00000] in <filename unknown>:0 
 
   at Mono.CSharp.Driver.Main (System.String[] args) [0x00000] in <filename unknown>:0 
 

I have set all the permissions of the drive, the folders, and the files to be full access for everything. I had this error some time ago, but I had fixed it by turning off McAfee Realtime Scanning. But as you can see, now I'm getting it again.

I'm not sure what is causing it, so any tips would be nice,

-Keith