Steam Steam Saying The Game Is Still Running Despite Being Closed And Dovetail Live Not Available?

So I fired up TSW 4 today to find a 230mb update for the game in my Steam library. I finish updating the game only for my Norton Anti-Virus to flag the game as being malicious. I created an exception to allow the game to run only to find that Dovetail Live refuses to connect. I decide to skip login and play on the ECML anyway. After playing for a bit and closing the game down, I come back later to find the game refusing to launch and find Steam reporting the game as still running despite being closed down. I open up the task manager and it's reporting the game as running and refuses to close forcefully, even the taskkill command refuses to close the game down. What confuses me the most is that TSW 4 was running perfectly fine last night with no issues and TSW 3 runs perfectly fine with a Dovetail Live connection, did the update break the game for me? Even after a complete reinstall I'm having the issues mentioned above.

Is this happening to anyone else? Any help would be much appreciated!

 

Update: I went ahead and completely disabled my anti-virus and this seems to have fixed the issue. Norton is the culprit, refusing to start the game after today's update.