There was an error handling the request
Scenario: you use auto port forwarding feature, when clicking the battle.net button you get "There was an error handling the request"
1. Quit the game.
2. Disable port forwarding function.
3. Launch the game, connect until login screen. Close the game.
4. Re-enable port forwarding function. Connection should now go through.
This problem appears when game tries to download cache files from bnet and is blocked by port forwarding. We are investigating the issue to completely resolve it.