ArenaNet has said it is "working around the clock" to try and fix "a couple [of] serious bugs" currently plaguing Guild Wars 2.

The hotly-anticipated MMO launched this morning following a three-day Headstart weekend, but the launch has been hampered by numerous problems, with users experiencing login errors and issues with the game's overflow servers.

Players have reported problems when switching maps, resulting in them being separated from their guild and thrown into the game's overflow servers, which are used to handle over-population.

The trading post, which functions as Guild Wars 2's player-to-player auction house, has also been temporarily taken offline.

"We currently have a couple serious bugs with one of our important back end systems," a spokesperson for ArenaNet told

"This error is causing the loss of trading post, players to sometimes be separated and unable to travel to each other when switching maps and entering overflow servers, and numerous guild errors.

"We are very sorry for this inconvenience and are currently working around the clock to try and remedy this error."

Nonetheless, the errors haven't appeared to put off many players.

More than 400,000 players logged in concurrently during the game's Headstart weekend, with one particular player already hitting the game's level cap.