Advanced Forum Error When Posting
The error has nothing to do with the Advanced Forum module, the error is coming from the IP address manager module. From it's error message, it looks like it's trying to insert a record that already exists. It could be a problem with how you upgraded that module (your dir suggests its version 1.4, but the line number matches the latest 2.0-beta) or it could be a bug. 

Either way, if you're not concerned with preserving historical data in the module, uninstalling, removing, and reinstalling the IP address manager module would be one way to get rid of the error.