You will need to check it with your system administrator, as I have mentioned it seems that you have a special error handler configured which does not respect @ to suppress warnings and it generates an error instead.
Alternatively you can rewrite that line to account the case when ? is not present in the code, but in that case you will need to do that every time. We might consider adding it in our future releases. Something like this should do the trick:
$url_params = explode('?', $_SERVER['REQUEST_URI']);
$request_uri = $url_params[0];
if(isset($url_params[1]))
$query_params = $url_params[1];
else
$query_params = '';
Thanks! ??