Bosh error message on Debian server

HI, I have a debian server. I am using xmpphp library for bot development. When I create a bot using the xmpp file it works fine, but when I try to use bosh it generates a fatal error.

Fatal error: Exception Exception "Exception" with message "String could not be parsed as XML" in /var/www/testlib/XMPPHP/BOSH.php:75 Stack trace:

0 / var / www / testlib / XMPPHP / BOSH.php (75): SimpleXMLElement -> __ construct ('')

1 / var / www / testlib / index.php (14): XMPPHP_BOSH-> connect ('myserver')

2 {main} thrown into /var/www/testlib/XMPPHP/BOSH.php on line 75

Please help me with this

thanks