Issue: Bug when enabling presets discussion topic

ErrorException: [E_WARNING] strlen() expects parameter 1 to be string, array given src/addons/vw/vw/_core/model/string/vw.php:611

Stack trace
#0 src/addons/vw/vw/_core/model/string/vw.php(611): XF::handlePhpError(2, '[E_WARNING] str...', '/home/admin/web...', 611, Array)
#1 src/addons/vw/vw/_core/controller/dm/base/vw.php(85): vw_String_Model->mb_clean(Array, '?')
#2 src/addons/vw/vw/XF/Entity/EntityBase.php(408): vw_DM_Base_Controller->verify_utf8(Array)
#3 src/XF/Mvc/Entity/Entity.php(613): vw\vw\XF\Entity\EntityBase->_verifyValueCustom(Array, 'prefixlist', 5, Array)
#4 src/addons/vw/vw/XF/Entity/EntityBase.php(400): XF\Mvc\Entity\Entity->set('prefixlist', Array, Array)
#5 src/addons/vw/vw/_core/controller/dm/xf2.php(208): vw\vw\XF\Entity\EntityBase->set('prefixlist', Array)
#6 src/addons/vw/vw/_core/controller/cp/area/vw.php(471): vw_DM_Controller_XF2->set('prefixlist', Array)
#7 src/addons/vw/vw/_core/controller/cp/area/vw.php(200): vw_CP_Area_Controller->set_area_fields(Array)
#8 src/addons/vw/vw/_core/controller/cp/area/vw.php(173): vw_CP_Area_Controller->process_save(Array)
#9 src/addons/vw/vw/_core/controller/cp/area/vw.php(64): vw_CP_Area_Controller->save()
#10 src/addons/vw/vw/Admin/Controller/Wiki.php(103): vw_CP_Area_Controller->execute('save', 'post')
#11 src/addons/vw/vw/Mvc/Dispatcher.php(30): vw\vw\Admin\Controller\Wiki->_actionIndex(Object(XF\Mvc\ParameterBag))
#12 src/addons/vw/vw/Admin/Controller/Wiki.php(51): vw\vw\Mvc\Dispatcher::dispatch(Object(vw\vw\Admin\Controller\Wiki), 'index', Object(XF\Mvc\ParameterBag))
#13 src/XF/Mvc/Dispatcher.php(350): vw\vw\Admin\Controller\Wiki->actionIndex(Object(XF\Mvc\ParameterBag))
#14 src/XF/Mvc/Dispatcher.php(257): XF\Mvc\Dispatcher->dispatchClass('vw\\vw\\Admin\\Con...', 'Index', Object(XF\Mvc\RouteMatch), Object(vw\vw\Admin\Controller\Wiki), NULL)
#15 src/XF/Mvc/Dispatcher.php(113): XF\Mvc\Dispatcher->dispatchFromMatch(Object(XF\Mvc\RouteMatch), Object(vw\vw\Admin\Controller\Wiki), NULL)
#16 src/XF/Mvc/Dispatcher.php(55): XF\Mvc\Dispatcher->dispatchLoop(Object(XF\Mvc\RouteMatch))
#17 src/XF/App.php(2184): XF\Mvc\Dispatcher->run()
#18 src/XF.php(391): XF\App->run()
#19 admin.php(13): XF::runApp('XF\\Admin\\App')
#20 {main}
Request state
array(4) {
  ["url"] => string(21) "/admin.php?wiki/area/"
  ["referrer"] => string(57) "https://web.com/admin.php?wiki/area/&areaid=4&do=edit"
  ["_GET"] => array(1) {
    ["wiki/area/"] => string(0) ""
  }
  ["_POST"] => array(25) {
    ["panel"] => string(4) "area"
    ["do"] => string(4) "save"
    ["_xfToken"] => string(8) "********"
    ["areaid"] => string(1) "4"
    ["prefixid"] => string(1) "0"
    ["title"] => string(13) "List of Books"
    ["parentid"] => string(1) "0"
    ["displayorder"] => string(1) "0"
    ["autoprotect"] => string(1) "0"
    ["prefixlist"] => array(1) {
      [-1] => string(12) "[Any prefix]"
    }
    ["allowtypes"] => array(1) {
      [0] => string(8) "Any type"
    }
    ["langlist"] => array(1) {
      [0] => string(14) "[Any language]"
    }
    ["templaterules"] => array(1) {
      ["value"] => string(0) ""
    }
    ["topiclist"] => array(2) {
      [0] => string(21) "[User-created topics]"
      [4] => string(7) "Test123"
    }
    ["sort"] => string(10) "lastupdate"
    ["sortorder"] => string(4) "desc"
    ["sortfilter"] => string(1) "0"
    ["options"] => array(10) {
      ["list_tiled"] => string(5) "16384"
      ["page_img"] => string(1) "2"
      ["page_bbcode"] => string(1) "4"
      ["page_smile"] => string(1) "8"
      ["page_media"] => string(4) "4096"
      ["comment_img"] => string(2) "32"
      ["comment_bbcode"] => string(2) "64"
      ["comment_smile"] => string(3) "128"
      ["comment_media"] => string(4) "8192"
      ["untabbed"] => string(1) "0"
    }
    ["autolink"] => string(1) "1"
    ["setstyleid"] => string(1) "0"
    ["blocklist"] => array(1) {
      [0] => string(11) "[Any block]"
    }
    ["url"] => string(40) "https://web.com/admin.php?wiki/area/"
    ["_xfRequestUri"] => string(38) "/admin.php?wiki/area/&areaid=4&do=edit"
    ["_xfWithData"] => string(1) "1"
    ["_xfResponseType"] => string(4) "json"
  }
}

if ($type == \XF\Mvc\Entity\Entity::STR AND $value !== null AND $value !== '')

if ($type == \XF\Mvc\Entity\Entity::STR AND is_string($value) AND $value !== '')

	public function get_parent_node(&$item)
	{
		if (empty($item['pageid']))
		{
			return false;
		}

		$accesskey = 'Page';

		if (!empty($item['areaid']) AND $item['pageid'] == $item['areaid'])
		{
			// save 1 query in this case
			$accesskey = 'Area';
		}

		return vw_Hard_Core::controller('Fetch')->get($accesskey, $item['pageid']);
	}

	public function get_parent_node(&$item)
	{
		if (empty($item['contentid']))
		{
			return false;
		}

		$accesskey = $item['contenttypeid'];

		if (!empty($item['areaid']) AND $item['contentid'] == $item['areaid'] AND $item['contenttypeid'] == vw_Hard_Core::model('Node')->id('Page'))
		{
			// save 1 query in this case
			$accesskey = 'Area';
		}

		return vw_Hard_Core::controller('Fetch')->get($accesskey, $item['contentid']);
	}