Displays directory access error in file system resource manager.

Assets/Cryville/Crtr/Browsing/FileSystemResourceManager.cs

@@ -1,8 +1,10 @@
 using Cryville.Common;
+using Cryville.Crtr.UI;
 using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using System.Security;
 
 namespace Cryville.Crtr.Browsing {
 	internal class FileSystemResourceManager : IPathedResourceManager<FileSystemEntry> {
@@ -57,10 +59,20 @@ namespace Cryville.Crtr.Browsing {
 #error No root path handling logic
 #endif
 				_cd = new DirectoryInfo(path);
+				try {
 					_items = _cd.GetFileSystemInfos()
 						.Where(i => i is DirectoryInfo || _extFilter.Contains(i.Extension))
 						.Select(i => new FileSystemEntry(i)).ToArray();
 				}
+				catch (SecurityException ex) {
+					Popup.CreateException(ex);
+					return;
+				}
+				catch (UnauthorizedAccessException ex) {
+					Popup.CreateException(ex);
+					return;
+				}
+			}
 			ApplyFilter();
 			DirectoryChanged?.Invoke();
 		}