I wanted to reset the grid and delete all the current sections/rows/blocks (I'm not sure what they are called), so I clicked the delete button to the right for each of the blocks. Now the grid is empty, but since there are no blocks to place content in, I can't place anything in the grid. And I can't find any way to add a block to a currently empty grid.
This is how it looks now:
Am I missing something or is this a bug?