The cheat protection for dirty bomb flags a lot of antivirus programs and the .dll gets vaulted and in most cases wont let the user know. AVG does do this.
The fix for dirty bomb not launching is to set the entire dirty bomb folder in your anti-virus exception list and re-verify the game files so the .dll will be replaced in the folder.
There is no need to uninstall your anti-virus as it can be dangerous. The best method to test if your anti-virus is conflicting with dirty bomb is to temporarily disable it to see if it launches. If it does then the anti-virus is the problem, be sure to re-enable and make the game an exception and go from there.