Help!! Cannot drag and drop inside editor!

Hello, I’m having this weird problem since yesterday. I cannot drag and drop anything anymore inside Unity Editor. I even tried to reinstall and the same problem is there.

The console gives me this error each time I try to drag and drop:

No Drag&Drop has been setup. Please
UnityEditor.DockArea:OnGUI()

And the bottom description of this error is this:

/Applications/buildAgent/work/6bc5f79e0a4296d6/Editor/Platform/OSX/DragAndDrop.mm

Can you help me please ? I cannot work with Unity anymore… T_T

Thank you.

UPDATE

Alright, I fixed my own problem by restarting the computer. Weird bug!! >_<

If you are having this problem in 2015 check this.

Unity uses NSPasteboard (OSX shared manager for clipboard) to hold the data for Drag&Drop, so any process that monitors/modifies the clipboard may be messing with the Drag&Drop.

In my case was the Pushbullet Chrome extension “Universal Copy & Paste” feature, by disabling it on the PushBullet options the problem seems to disappear, note you still need a restart after disabling it.

The problem was happening to me in Mavericks, and a Yosemite upgrade did’t helped, so probably not related to the OS in this case.

So check if you have any software that may be messing with the clipboard.

We found an answer on Mac OS X Yosemite. There was a Chrome extension that was generating notifications that would for some reason break drag and drop. Hope this helps someone out there in the future.

I wrote a small tool to help me work without drag and drop. this will place the selected prefab in the scene:

using UnityEditor;
using UnityEngine;

public static class WhenDragAndDropFailes
{
	[MenuItem("Assets/Instantiate In Scene %i")]
	public static void PlacePrefabInScene ()
	{
		if (Selection.activeObject != null) {
			PrefabUtility.InstantiatePrefab (Selection.activeObject);
		}
	}
}

make sure none of your keyboard keys are stuck. Happened to me.