Object of class vB_Template could not be converted to string

[Wedframe]

Hi. Please help me with modification of plugin. This plugin work perfectly on the default style, but on installed custom style his generate php-errores:

Object of class vB_Template could not be converted to string....
strpos() expects parameter 1 to be string, object given...

Ofcause after this the page not loading....
I found hook and localized code what gives this errores. Its in parse_template

PHP Code:

if ($vbulletin->options['legacypostbit'] AND isset($vbulletin->templatecache['postbit_legacy']) AND is_member_of($vbulletin->userinfo, unserialize($vbulletin->options['mkp_self_moderation_group'])))
        {
            $template =& $vbulletin->templatecache['postbit_legacy'];
        } 


If I comment action of statement "if"

PHP Code:

if ($vbulletin->options['legacypostbit'] AND isset($vbulletin->templatecache['postbit_legacy']) AND is_member_of($vbulletin->userinfo, unserialize($vbulletin->options['mkp_self_moderation_group'])))
        {
            //$template =& $vbulletin->templatecache['postbit_legacy'];
        } 


then page load without errores, but plugin not work correctly.
Thanks for any help!