If this is something you placed there or something that's part of the Farm map, then yes, there are some random tiles which prevent placing buildings in certain locations. Also Animals can prevent placing buildings, though I seem to recall that this was addressed in v1.5 where you could scoot them out of the way? Anyhow I'm usually thwarted by Torches I've left in random places which certainly will prevent you from moving a building on top of them.
So it's back to the Farm... Oh! and change all the machines which are done processing, grab all the Torches, grab all the Truffles, toss the processed stuff in the Shipping Bin, and... what was I doing? And then notice the animals are heading back into the Coop and Barn, which means it's 6pm and I forgot to get back to Robin. And it's Monday. Of course.