List view swipe widget configuration error: Cannot read property add of undefined

Hi all,  Out of nowhere I get the following error with the List view swipe widget (in the console): ListViewSwipe_widget_ListViewSwipe_0 configuration error: Cannot read property 'add' of undefined   I changed nothing within the widget, nor anything within the list that I have this widget referring to. I also can't find anything in the widget that has something to do with the 'property add’ so I'm at a loss here. On top of the list it gives the error: The weird thing is, that for SOME of the list items, it displays the ‘listview swipe background’ underneath the item and I am unable to swipe these items. On other items, however, there is no problem whatsoever and I can swipe these items. They are all items of the same kind, there is no difference between the list items.  In the following screenshot you will (hopefully) see what I mean: The top item in the list can be swiped and you only see the delete container while swiping, the other items have said container underneath itself and can't be swiped. I tried restarting the modeler but it didn't work ;) Does anyone have an idea where it's coming from?    Cheers, Sophie   EDIT: I see that I failed to add in my question that we retrieve messages with HTML in the description. We used the markdownviewer to display the messages including the original HTML (and thus styling). Apparently with these particular messages, something was wrong with the HTML. We managed to solve it by using CustomString where we strip the String of its HTML (as we don't need the HTML in this overview, only on the detail page) using the HTMLToPlainText Java Action from the community commons. 
1 answers

Hi Sophie,

Is there an other message in the browser console?

LVS no '${displayName}' found named ${name}. It should be placed inside the list view

This error is probably caused by an element that can not be found. Do the class names of the contains still match, do they have conditional visibility? Did you change Mendix version?

An error trace might be use full to find the cause.

Cheers, Andries