FileIOPermissionAccess.Append, FileIOPermissionAccess.Read, FileIOPermissionAccess.Write, and FileIOPermissionAccess.PathDiscovery access to a file or directory. FileIOPermissionAccess.AllAccess represents multiple System.Security.Permissions.FileIOPermissionAccess values and causes an ArgumentException when used as the access parameter for the FileIOPermission.GetPathList(FileIOPermissionAccess) method, which expects a single value.