It would seem that PHPExcel does not correctly identify the file type, it relies partly on the extension and my assumption is that it is wrong (xls-> he tries a reader Excel5, finds that it does not, it considers that this is a csv).
The first two characters displayed as PK, renames your file in xlsx or force the use of an Excel 2007 reader
The first two characters displayed as PK, renames your file in xlsx or force the use of an Excel 2007 reader