Plane is not appearing as blue in render As a beginner I seem to be having a lot of trouble.  Here are some other questions I have asked along the way but found that I have to start again.

This time, my plane is not appearing.  It appears in Object mode, it only appears to be the correct colour in Material view.

Any solutions? I am sure it's simple.

My file is here.
For some reason your object has shadow catcher and dupli faces selected. Both prevent it being displayed in render view.