Mark - 2016-06-06

hi guys I've just installed phpvirtualbox in my centos 7 and when I try to get in I have this error:
Exception Object
(
[message:protected] => Error logging in to vboxwebsrv.
[string:Exception:private] =>
[code:protected] => 64
[file:protected] => /var/www/html/phpvirtualbox-5.0-5/endpoints/api.php
[line:protected] => 134
[trace:Exception:private] => Array
(
)

[previous:Exception:private] =>

)

can you help me to understand and fix it?
thanks