Error Code 901 is an Xbox-only error that appears when Roblox cannot get you signed in, on both Xbox One and Series X|S. On screen it usually reads "Authentication Error. Trouble communicating with Roblox servers. Please try again."
Despite that wording, the servers are rarely the problem. Roblox itself names exactly three situations that trigger 901: you were creating a new account, you were signing in to an existing one, or the account tied to your Gamertag has been moderated.
That makes 901 friendlier than most codes in the Roblox error codes and fixes list. Find your situation below and run only the fix that matches it.
| What you were doing | Your fix |
|---|---|
| Creating a new Roblox account | Pick a username that follows the rules |
| Signing in or linking an account | The same-network trick |
| Nothing new, and you may be banned | Check the account on another device, then appeal |
If it happened while creating an account, fix your username
The usual trigger here is a username that breaks Roblox's rules. The sign-up screen rejects it and hands you 901 instead of a clear explanation.
A valid username needs all of these:
- 3 to 20 characters
- Letters and numbers only, with at most one underscore, never at the start or end
- No inappropriate words or phrases
- No personal information, like your real name or birthday
Pick a name that passes every rule and try the sign-up again. That is the whole fix.
If it happened while signing in, use the same-network trick
This is the most common 901, and Roblox's own fix for it is oddly specific: prove the login works on another device that is on the same internet as your Xbox.
- Quit the Roblox app on the Xbox and reopen it.
- If that changes nothing, restart the console: hold the Xbox button on the controller and choose Restart console.
- Log into the same Roblox account on a phone or computer connected to the same home Wi-Fi, and confirm it works there.
- Back on the Xbox, on that same network, sign in again.
- Still blocked? Open Roblox's settings on the Xbox, look for the account or unlink option, unlink the account, then sign back in.
The other-device check does double duty. If the login fails on your phone or computer too, the problem is the account itself, so jump to the moderation section below. And if the Roblox app on your PC will not stay open long enough to test, the fixes for Roblox closing on its own on PC will get it stable first.
If your account was moderated, check and appeal on another device
901 can simply mean the Roblox account connected to your Gamertag is banned or restricted. The Xbox will not tell you that directly, but any other device will.
Log into the account on a browser or phone. If the account is moderated, the notice shows up right after you sign in.
A temporary ban lifts on its own when its time runs out, so waiting is a real option. If you think the moderation is a mistake, appeal through the Roblox support form. Be aware that Roblox says submitting an appeal does not guarantee the ban is removed.
If none of that worked, update or reinstall Roblox
First, a ten-second check of the Roblox status page rules out a rare platform-wide outage. If Roblox itself is down, waiting is the only fix.
Otherwise, open My games & apps, find Roblox, and install any waiting update. If updating changes nothing, reinstall: go to My games & apps > Roblox > Manage game and add-ons > Uninstall all, then install Roblox again from the Store.
Reinstalling is safe. Roblox keeps your account data and progress in the cloud, not on the console, so removing the app deletes nothing that matters.
If Roblox is also failing on your PC while you test, work through the fixes for an error occurred and Roblox cannot continue to get one device working first.
