Issue: Undefined variable: category_node

This bug blocks us from adding new pages:

ErrorException: Undefined variable: category_node - vault/core/controller/dm/item/category/vw.php:416
Generated By: Bijou, Today at 19:16

Stack Trace
#0 /vault/core/controller/dm/item/category/vw.php(416): XenForo_Application::handlePhpError(8, 'Undefined varia...', '/home//d...', 416, Array)
#1 /vault/core/controller/dm/vw.php(118): vw_DM_Item_Category_Controller->delete_multiple(Array)
#2 /vault/core/controller/ui/assign/category/vw.php(328): vw_DM_Controller->delete_multiple(Array)
#3 /vault/core/controller/ui/edit/page/vw.php(628): vw_UI_Assign_Category_Controller->save_assignments(Object(vw_UI_Page_Controller_XF), Array, Array)
#4 /vault/core/controller/ui/edit/vw.php(273): vw_UI_Edit_Page_Controller->process_assignments(Object(vw_UI_Page_Controller_XF), Array, Array)
#5 /vault/core/controller/ui/page/vw.php(346): vw_UI_Edit_Controller->save(Object(vw_UI_Page_Controller_XF))
#6 /vault/core/controller/ui/page/vw.php(133): vw_UI_Page_Controller->save()
#7 /vault/core/controller/ui/page/xf.php(58): vw_UI_Page_Controller->execute()
#8 /vault/core/controller/ui/stack/vw.php(276): vw_UI_Page_Controller_XF->execute()
#9 /library/vw/XenForo/ControllerPublic/Wiki.php(70): vw_UI_Stack_Controller->execute()
#10 /library/XenForo/FrontController.php(369): vw_XenForo_ControllerPublic_Wiki->actionIndex()
#11 /library/XenForo/FrontController.php(152): XenForo_FrontController->dispatch(Object(XenForo_RouteMatch))
#12 /index.php(13): XenForo_FrontController->run()
#13 {main}
Request State
array(3) {
["url"] => string(75) "/wiki/?title=Trainwreck&do=save"
["_GET"] => array(2) {
["title"] => string(29) "Trainwreck"
["do"] => string(4) "edit"
}
["_POST"] => array(19) {
["message_html"] => string(203) "<p>

Diverse&nbsp;informatie&nbsp;en&nbsp;bronteksten

<br>

Oude&nbsp;Producttekst

<br>
Link:<br>

Nieuwe&nbsp;Producttekst

<br>

Status

<br>
Niet&nbsp;toegevoegd.</p>"
["_xfRelativeResolver"] => string(75) "/wiki/?title=Trainwreck&do=edit"
["query"] => string(0) ""
["removecategoryids"] => array(1) {
[0] => string(2) "71"
}
["reason"] => string(0) ""
["minor"] => string(1) "1"
["prefixid"] => string(1) "0"
["edittitle"] => string(31) "Trainwreck
["typelist"] => array(1) {
[14] => string(1) "0"
}
["_xfToken"] => string(8) "********"
["do"] => string(4) "save"
["section"] => string(1) "0"
["posthash"] => string(32) "a762540e0f2b365ec02fde813ffe9cba"
["poststarttime"] => string(10) "1526318106"
["revparentid"] => string(3) "408"
["loggedinuser"] => string(1) "4"
["sbutton"] => string(4) "Save"
["notifytype"] => string(1) "1"
["sub_options"] => array(2) {
["item_edits"] => string(1) "1"
["item_comments"] => string(1) "1"
}
}
}