Cannot move unit stack

I can't move my units out of one of my provinces, they won't move out of the province and anything that go's in their also can't get out. I've tried splitting them but that doesn't do anything, they split but then they don't move even though the arrow of direction is displaying where I'm moving them to and how long it will take for them to get there. I've tried reloading my game but that doesn't work either.