What is the Mode of the blank canvas? It needs to something like sRGB if it is a colour image you are trying to add to the canvas.
Is the image also open in Photoshop, or are you trying to drag it from outside Photoshop, and if so, where from?
What operating system are you using? (Windows 7? Apple 10.???
I got Windows 7. And the image is open in Photoshop. Yeah, it's RGB. So it should work when I drag it but it won't.
Just to be clear, it is the mode of the New document that I was asking about. Is that RGB? If it were indexed colour, for instance, that would preclude the dragging of an RGB image to it.
Yeah it's RGB