3: "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
   ^                                                   
found String where operator expected

Missing ';' above?

6: <title>Sécurité en ingénierie du Logiciel : une analyse inversée ...
   -------^                                                            
found bareword where operator expected (previous token underlined)

There is no previous '?' to match a ':' on line 6
6: <title>Sécurité en ingénierie du Logiciel : une analyse inversée ...
                                             ^
6:	unexpected character decimal 233 (é) in script
6:	unexpected character decimal 233 (é) in script
6:	unexpected character decimal 233 (é) in script
6:	unexpected character decimal 233 (é) in script
6:	Giving up after error
153:	To see 1 non-critical warnings rerun with -w
153:	To save a full .LOG file rerun with -g