Why can’t I drag and drop some elements?

Let’s say I have a start with a 2 column layout.

I now want to have 2 columns inside of the right column.

I can’t seem to create 2 columns inside of the right side.

So… I create 2 columns below and then try to drag into the right side – it doesn’t allow me!!

I’m thinking there are good reason why both the above aren’t allowed?

How do I get round this problem?

Thanks.