3.4 Upgrade: I can't edit Sidebar/Widgets anymore & Media upload by Drag-n-Drop

(sorry double post, but HTML seems messed up in my first post)

Saw same behavior today. Was uploading images after update to 3.4 and nothing happens when I drag and drop.

I am having exactly the same problem. Drag-and-drop doesn’t work, nor does the dropdown.

I’ve managed to work round it by using this tip from someone who had the same problem two years ago when upgrading to 2.9 9https://www.ads-software.com/support/topic/wordpress-widgets-not-working?replies=26):

1. Be sure you are on the widget page
2. Append ?widgets-access=on to the end of your url.
3. Enter
The above forced enable-accessibility to be turned on.

That works but it’s not really a permanent solution, and I found the dropdown wasn’t working on other pages in the Dashboard too.

Same problem here ??
So, thanks to Mariette for the workaround!

I worked out that it was the Google Custom Search plugin that was causing the problem but this has now been upgraded and the problem has gone away. Yay!