Unable to build tile

I'm not sure this willl always happen.

1) Clicked Build Tile button

2)  Mud Fell down blocking off the material to build the tile so had no material to build.  Correctly it grayed out the build tile button.

3) Dugout the mud granting enough material to build tile.

4) If I clicked the Build Tile button it acted like it was going to allow me to build but it would.

5) Clicking Build ladder got it out of the "stuck" state.