Blur
Issues And Fixes
Unable to Play Online
This is an issue which has remained unfixed since release; and essentially involves an inability to connect to online games, whether it is logging into the online service or actually locating games. The cause of the issue is Blur's overly strict reliance on port forwarding, although often ensuring uPnP is enabled and that the correct ports are forwarded will not actually solve the issue. As of now the only reliable way to play online is to use Virtual LAN (Local Area Network) software such as Hamachi or Tunngle, the latter of which still has an active Blur community.
To play Blur online via Tunngle, simply download and install the Tunngle client before logging in and searching 'Blur' in the search box to the left of the client. Enter the Blur room and you will connect to the VLAN system, meaning you can simply launch Blur and navigate to the Local Area Network multiplayer game mode, where Tunngle games will then become visible.