Cannot add modifiers? I am following one of Quill18's tutorials for Blender and Unity 3D. I have a very simple model with one object so far and need to add a second object.

The first model has multiple modifiers, the Mirror modifier being one of them. Now, I also need to apply the Mirror modifier to the new object.

Unfortunately, I don't see the option in the interface. When the first object is selected the relevant tab (spanner) exists and contains the correct modifiers and an "Add Modifier" button.

When the new object is selected, the tab also exists, but it is empty (doesn't contain any buttons whatsoever).

How can I add a modifier to the second object?

The .blend file: https://www.dropbox.com/s/6iyitaqp68cofen/Level1_2_objects.blend?dl=0

Screenshots: 





I use Windows 7 Home Premium on a 64-bit laptop.
Your properties panel is scrolled down. Try scrolling up with the mouse wheel or the scroll bar: