Using MeshFilter.mesh with static ground plane makes object turn into a plane.

I have two objects in my scene, a plane and a cube, both imported from blender, I have assigned a script to my cube that contains this line(I am sure it is this line as I used another script with only this line of code and the same thing happens)` Mesh mesh= gameObject.GetComponent().mesh;` . When the plane is static the cube turns into a plane ,the exact same size as the ground plane,on playing in the editor, its really annoying and I think its a glitch with unity but wanted to check here just in case its something else. Thanks in advance.