Can't drag, drop or open since 4.2.1

I’m sorry, but may I ask for a bit of clarification…
Is your problem with WordPress’s menu administration page (Appearance/Menus), or specifically/exclusively with the Custom Menu Wizard plugin (Appearance/Widgets, or Appearance/Customize)?

If your problem is solely with CMW then can I ask what you mean by “…can not drag or open the menus…”, because I don’t understand (the only “drag” capability that CMW provides is the ability to move its Assist overlay around the screen).

If it’s WordPress’s administration of Custom Menus that is proving troublesome then I’m afraid I don’t have an answer for you.

This website of my client is pretty big and about soccer statistics.

We are using custom menu wizard to generate different sidebar menu’s for different pages. As a result, we have a lot of different CMW widgets in de sidebar in Appearance/Widgets. It worked fine though, apart from some heavy scrolling when adding a new one. Other then that, we only use a search widget, rss widget and 1 widget from the plugin SportsPro.

From the plugins used in Appearance/Widgets, atm CMW gives the announcement that it isn’t tested with the current version of WordPress. So this is why I got the idea that it might have to do with a conflict between CMW and WordPress latest version. Everything worked fine untill that latest WP update.

Oh sorry, and what I mean is that I cannot use the arrow in the CMW widget in Appearance/Widgets, or drag it to a different order in the row or add a new one.

So as I understand it, in Appearance/Widgets…
1. You can’t create a new instance of CMW by dragging from the Available Widgets area onto a Widget Area
2. You can’t drag an existing instance of a CMW widget to a new position within its Widget Area
3. You can’t open an existing instance of a CMW widget by clicking on the down-arrow in the widget header

Hmmm … all these things are under WordPress control, not the widget’s (and I have no problem with my 4.2.1 installations).

I’m assuming that all 3 of these behaviours are only happening to CMW, ie. you can add other widgets to the Widget Area, move them around, and open and maintain them?

Are you able to maintain CMW widgets via the Customizer?

Do the CMW widgets (existing or new) react the same as other widgets when hovering over with the mouse (ie. cursor changes to hand or move, and outline darkens)?

Do you get any javascript errors when attempting to drag a new/existing instance, or open an existing instance?

If you View the page source – or Inspect the widget – is there any evidence of errors in the HTML that CMW is producing (I realise this might be difficult to tell without a comparison, but a quick look should show up any PHP errors, for example, and the code should at least like the expected widget form fields)?

You mention “a lot” of CMW widgets : how many instances of CMW in one Widget Area? (I don’t see why this should have any effect on anything, but I’m curious)