Fixes bug that no mime_type_content is called if there is on file.

extension/Classes/Core/Helper/HelperFile.php

@@ -39,7 +39,7 @@ class HelperFile {
     }
 
     /**
-     * Returns a uniqe (use for temporary) filename, prefixed with QFQ TMP_FILE_PREFIX
+     * Returns a uniq (use for temporary) filename, prefixed with QFQ TMP_FILE_PREFIX
      *
      * @return bool|string
      */

extension/Classes/Core/Report/Download.php

@@ -516,6 +516,13 @@ class Download {
             case DOWNLOAD_MODE_EXCEL:
                 $excel = new Excel();
                 $filename = $excel->process($tmpFiles, $tmpData);
+
+                if (empty($filename) || !file_exists($filename)) {
+                    throw new \DownloadException(json_encode(
+                        [ERROR_MESSAGE_TO_USER => 'Newly created Excel file is broken.',
+                            ERROR_MESSAGE_TO_DEVELOPER => "File: '$filename''"]), ERROR_IO_READ_FILE);
+                }
+
                 if (empty($vars[DOWNLOAD_EXPORT_FILENAME])) {
                     if (HelperFile::isQfqTemp($filename)) {
                         $vars[DOWNLOAD_EXPORT_FILENAME] = DOWNLOAD_OUTPUT_FILENAME . ".xlsx";