diff --git a/sao/src/screen.js b/sao/src/screen.js
index 85db45d234..0f496fd362 100644
--- a/sao/src/screen.js
+++ b/sao/src/screen.js
@@ -936,7 +936,7 @@
             var views = this.views.concat(this.view_to_load)
             var next_view_index = (this.view_index + 1) % views.length;
             var next_view = views[next_view_index];
-            if (typeof next_view != 'string') {
+            if (next_view && (typeof next_view != 'string')) {
                 next_view = next_view.view_type;
             }
             return next_view;
diff --git a/tryton/tryton/gui/window/view_form/screen/screen.py b/tryton/tryton/gui/window/view_form/screen/screen.py
index 12b6c3042f..655da6c632 100644
--- a/tryton/tryton/gui/window/view_form/screen/screen.py
+++ b/tryton/tryton/gui/window/view_form/screen/screen.py
@@ -547,7 +547,7 @@ class Screen:
         views = self.views + self.view_to_load
         next_view_index = (self.view_index + 1) % len(views)
         next_view = views[next_view_index]
-        if not isinstance(next_view, str):
+        if next_view and not isinstance(next_view, str):
             next_view = next_view.view_type
         return next_view