diff --git a/src/octoprint/static/js/app/helpers.js b/src/octoprint/static/js/app/helpers.js
index a83cd5ed..abd80436 100644
--- a/src/octoprint/static/js/app/helpers.js
+++ b/src/octoprint/static/js/app/helpers.js
@@ -1000,10 +1000,13 @@ function setOnViewModelsIf(allViewModels, key, value, condition) {
 }
 
 function callViewModels(allViewModels, method, callback) {
+    if (!allViewModels) return;
     callViewModelsIf(allViewModels, method, undefined, callback);
 }
 
 function callViewModelsIf(allViewModels, method, condition, callback) {
+    if (!allViewModels) return;
+
     if (condition == undefined || !_.isFunction(condition)) {
         condition = function() { return true; };
     }
diff --git a/src/octoprint/static/js/app/viewmodels/wizard.js b/src/octoprint/static/js/app/viewmodels/wizard.js
index a1370215..fbc2e37b 100644
--- a/src/octoprint/static/js/app/viewmodels/wizard.js
+++ b/src/octoprint/static/js/app/viewmodels/wizard.js
@@ -193,7 +193,7 @@ $(function() {
             if (!self.finishing && self.isDialogActive()
                 && hasDataChanged(self.settingsViewModel.getLocalData(), self.settingsViewModel.lastReceivedSettings)) {
                 var preventSettingsRefreshDialog = false;
-                callViewModels(allViewModels, "onWizardPreventSettingsRefreshDialog", function(method) {
+                callViewModels(self.allViewModels, "onWizardPreventSettingsRefreshDialog", function(method) {
                     // if any of our methods returns that it wants to prevent the dialog
                     // we'll need to set preventSettingsRefreshDialog to true
                     //