definitely not intended! Sorry this happened to you. The game usually saves when loading the map. I would need more information though to find the cause and fix it: - you see the finished first map and can click on anything? - where did you leave the game (just after the bossfight?)
The game should work offline and online, but the problem might have occurred if you turn your internet off during playing (and the game still tried to save online or sth). Sorry I didn't test this exception that well.
