Port forwarding should not be needed if you are using universal plug and play. That said, check in accessibility options and see what the game is reporting for your NAT type. If it’s not open, you may need to go into your router and put your PC’s IP in a DMZ and/or adjust router firewall settings. Set a static IP for your PC.

[quote]ERROR CODE: BEE ALL PLATFORMS BEE, FLY, and LION error codes can be caused by general disconnections between you and the various routes your traffic takes across the internet to get to Bungie. [b]This includes packet loss or disconnections between your home network and Bungie (such asISP saturation or general internet congestion). It can even be caused by certain WiFi setups, faulty in-home wiring, or other issues that require on-site support or expert investigation. [/b] [b]Disconnects of this type can also be caused by bandwidth being claimed by other devices and applications.[/b] It may be necessary to avoid file-sharing, video streaming or other bandwidth intensive tasks on any device connected to your network while playing Destiny, including console applications that run  in the background or in a window as you game. If you hit this frequently, please follow the suggestions in our Network Troubleshooting Guide to see if troubleshooting your setup, or switching from a wireless to a wired setup improves your experience. During investigation, Bungie has seen users hitting these errors in geographic clusters in different places at different times. For example, we recently detected 25% packet loss from the UK at the same time a number of users located there saw errors. Sometimes these issues can arise with ISP outages, resolving on their own over time. If you have performed all of the troubleshooting steps called out above and are still hitting these errors, you may not be able to resolve this issue by changing your home network configuration. Please contact your ISP for further assistance.[/quote] I've highlighted what may be most petinent to you. Also, here is a link to the network troubleshooting guide. [url]https://www.bungie.net/en/Support/Troubleshoot?oid=12915[/url]