I am using the latest beta build, but this issue occurs on the stable release as well. I am completely unable to drag and drop assets of any kind into my projects. This is only a minor issue, as I can still open the folders and/or use the "Import" option to successfully bring in assets. It is only a convenience issue and thus not a high priority if it's something more than an easily-resolved bug.
While I'm here, I am also unable to delete assets from anywhere but the scene explorer. I have to right click and choose "Delete." I am no longer able to simple press my "Delete" key, nor is there a right-click context menu option within the viewport windows to permit deletion. This might be intentional, not sure. A temporary workaround is to use the cut shortcut (CTL+X) to pseudo-delete. This works well enough for now.
See attached screenshot for image of current right click context menu.