Fix adding asset restrictions

core/views/assets.py

@@ -86,6 +86,10 @@ class AssetRestrictionCreate(
     submit_url_name = "assetrestriction_create"
     submit_url_args = ["type", "group"]
 
+    def form_invalid(self, form):
+        """If the form is invalid, render the invalid form."""
+        return self.get(self.request, **self.kwargs, form=form)
+
     def pre_save_mutate(self, user, obj):
         try:
             assetgroup = AssetGroup.objects.get(pk=self.kwargs["group"], user=user)