I moved a Mill earlier that didn't move. It's possible that I didn't have the resources at the time but I thought I had.
Either way the mill didn't move. It's now displaying the red exclamation mark with the magnifying glass showing.
When I click on the mill now all I see is the footsteps to the nearest store, the Building window doesn't appear so I can't upgrade it or do anything else to it.
Any ideas?