Unable to Drag and Drop Folder/Assets into "Project" editor window.

The issue is explained in the title, I am unable to take a folder from my desktop and drag it into the “Project” tab.

I was able to do this earlier, re-installing does not solve the problem.

I am unable to provide a way to re-create this problem and I see no reason in a screenshot of the Unity UI as all you would see would be a Unity UI.

I have been searching for a solution but so far the the replies there is either “restart computer” or “create new project and open old project for it to work again” neither which have worked.

Just so people up there get knowledge, I work with Unity on 2 different computers, and since I upgraded one of them to Windows 8/8.1 I was NEVER able again to import any kind of asset using drag’n’drop in the win8 one. The projects keeps traveling from one computer to another, every one of them (old and new ones) always work on win7 machines, but in my win8 ones they never do, and never did. Every other program I work with in windows8 still provides me drag&drop functionality.

Maybe Unity just got something pass in their build, like new windows8 inputs API (which has frustrated a lot of people regarding mouse stuttering ingame).
Please, take a time to look at it… Drag&Drop is crucial to end-user confort and straight workflow…

Ty in adivce.

The problem for me was the Windows DPI setting that it always restored based on my account. In “Display” in the Control Panel, I had it set to 150% on text size. I think the pixel mapping to validate the state of the drag drop operation is not correctly using the DPI setting in Windows. Setting it to 100% works around the problem.
Set at 150%, it blocks drag/drop.