JSON parsing error is corrected !!!
in fact, notice php errors due to bgp.php (or index.php !) appear during processing of php and appear in html resulting of that processing… so json can't decode <br /> and other html tags…
If someone can find a more efficient solution and the cause of those notices !!!

.htaccess of ajxp folder contains directive to hide php errors which lead to json parsing error (notice messages in bgp.php processing !!!!)
corrections of all configuration.php require_once in ajaxp files which need this inclusion
correction in mobile analyze http header