@Clouseau:
…..
Is there any work around to fix this?
Yep.
Telling us more / the whole story.
The error says that an instance of the GUI is already running, thus the 'bind' error - but probably not in a good shape.
Check out the logs files after booting. Something must show up that is not "normal".
edit : I can rip out the WAN cable (WAN connection for me is a DHCP client, connected to an up stream ISP router) and this does not break my GUI.
pfSense works just fine (well, sort of) without an enabled WAN connection, because,remember, when pfSense was started the very first time, right after you installed it, there was NO WAN connection setup, and you had to use the GUI to setup LAN first.