Index: branches/RC/core/kernel/utility/formatters/upload_formatter.php
===================================================================
diff -u -N -r10098 -r10452
--- branches/RC/core/kernel/utility/formatters/upload_formatter.php	(.../upload_formatter.php)	(revision 10098)
+++ branches/RC/core/kernel/utility/formatters/upload_formatter.php	(.../upload_formatter.php)	(revision 10452)
@@ -101,7 +101,11 @@
 				$max_filesize = isset($options['max_size']) ? $options['max_size'] : MAX_UPLOAD_SIZE;
 
 				if (getArrayValue($options, 'allowed_types') && !in_array($value['type'], $options['allowed_types'])) {
-					$object->SetError($field_name, 'bad_file_format', 'la_error_InvalidFileFormat');
+					$error_params = Array (
+						'file_type' => $value['type'],
+						'allowed_types' => $options['allowed_types'],
+					);
+					$object->SetError($field_name, 'bad_file_format', 'la_error_InvalidFileFormat', $error_params);
 				}
 				elseif ($value['size'] > $max_filesize) {
 					$object->SetError($field_name, 'bad_file_size', 'la_error_FileTooLarge');