Diablo 4 Error Code 401003: How to Fix & What It Means

Like a lot of games its size, Diablo 4 has experienced problems on launch that are inhibiting players from getting into the demon slaying action. One of the most prominent has been Diablo 4 Error Code 401003, but what does it mean, what causes it and how can it be fixed?

Diablo 4 Error Code 401003: Causes & What It Means

In Diablo 4, the Error Code 401003 occurs when the connection from the game to your network is lost. It is believed to generally be a result of client-side problems, meaning players affected need to troubleshoot and tweak a few things to solve the issues and get back into the action.

Naturally, there are a lot of reasons it can occur, ranging from Blizzard server problems (which the developers continue to address off the back of the game’s launch) to issues with players’ own home networks.

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[#DiabloIV] We're currently investigating an issue affecting our authentication servers, which may result in failed or slow login attempts.

— Blizzard CS – The Americas (@BlizzardCS) June 6, 2023

It should become less common as we move away from Diablo 4’s launch and problems of this nature are eradicated but, thankfully, there are multiple things we can try to bypass the issue and get you into Sanctuary.

Diablo Error 401003 Solutions & How To Fix

The most reliable fix for Error Code 401003 in Diablo 4 is to restart your game. Whatever platform you’re playing on, this has been touted as the most reliable solution. It’ll re-establish the connection between your home network and the Blizzard servers and – hopefully – let you in to play.

If that doesn’t work, we recommend restarting your console or PC. This will restart your connection to your home network and Blizzard’s servers, reducing the chance of errors arising from either.

Another way to fix the problem is to restart your home network. As previously mentioned, the Error Code can occur when there are issues with the client-side. Restarting your home network will refresh your own internet and minimize the chances that this is the route cause.

Hopefully one of these fixes has solved the Diablo 4 Error Code 401003. Be sure to report your problems to Blizzard Support, who’ll hear your concerns and implement changes in the near future to reduce the prevalence of bugs and glitches. After all, everyone just wants to play, choose a class and get into tackling Lilith.