GTA 5 Online went live today, but Rockstar warned of major problems. GTA 5 gamers have been faced with error messages and complained the system is not working, while trying to access the multiplayer feature online.

According to NowGamer.com, the online multiplayer update for GTA 5 continues to roll out today, but players are being plagued with "Failed To Host GTA Online Session" errors, preventing access to the online gameplay part of GTA 5.

Another error message that frequently appears is "Rockstar cloud servers are unavailable."

Users on NeoGAF are having the same problem, GTAForums have mentioned the opening race on GTA Online isn't working problem while GameFAQs members have mentioned frequent crashes, NowGamer.com reports

Gamers who have been able to play GTA Online are reporting that they can't save their progress.

Due to "unanticipated additional pressure on the servers due to a significantly higher number of players [than expected]", Rockstar warned that play on GTA 5 Online might be "temperamental" for the first few days, The Independent reports.

"We are working around the clock to buy and add more servers," said the game's developers in a blog post.

It warned of the "typical growing pains" which accompanied a new online game including crashes, glitches and "crazy bugs," The Telegraph reports.

Rockstar Games also wrote on their Twitter today: "For those trying to get into GTA Online today, please bear w/ us on some day one tech connection issues that we're working to stabilize asap"

Perhaps the errors have something to do with the millions of players trying to log in; GTA 5 broke record sales when it launched last month, bringing in £500 million in its first 24 hours on sale and £1 billion after three days, The Telegraph reports.

Anyone who has bought a copy of GTA 5 will have free access to the online portion of the game, through a small update that can be downloaded from either the PlayStation Network or Xbox Live. Users can access online play through the game menu or by selecting the fourth (currently empty) slot in the game's character selection wheel, The Independent reports.

Rockstar will be releasing updates and fixing glitches in the coming weeks and has urged players to get in touch when problems arise, according to The Telegraph.