Units not able to conquer a Province.

Game Number: 5,532,549

Summary: I was gathering up infantry to take a province, and successfully defeated the defending force. However, when I went to the center of the province, (all troops in province are defeated), it wouldn't let me take it. I've taken my troops out and put them back but it's still owned by the enemy. There is also one of my allies who can't take the province either. Below are screenshots of the situation:

Screenshots:

click for imgur link

(i couldn't get it to work)

EDIT: THE PROVINCE REBELLED SO I HAVE THE PROVINCE NOW