To reproduce:
1. Import user's attached sprite (or any other)
2. In sprite's Inspector window change texture type to Sprite(2D and UI) and sprite mode to multiple, apply changes
3. Drag the sprite from Project window to Scene window

Expected: console warning "Texture being dragged has no Sprites." appears once
Actual: console warning "Texture being dragged has no Sprites." keeps appearing as long as sprite is being dragged on Scene window

Reproduced in: 5.3.8f2, 5.4.5p2, 5.5.4f1, 5.6.1p2, 2017.1.0b8, 2017.2.0a1

Verified fixed on: 2017.2.0b3 (410785043cbf)