Changing UVWs

I am trying to change the UVWs by selecting the object and changing the UV Tiling Scale.

No matter what I do - as soon as I change the UV Tiling, the texture map is gone.
Box, Cylinder, Planar.

And no matter what channel I chose.
What am I missing here?

Is there any quick tutorial that shows the process step by step?
How to change the UVW’s with the Projection Type and the Tiling?

Thanks a lot!