Roblox throws a number at you, the game closes, and nothing on screen says what happened. Roblox's own support site keeps one index of the error codes it documents, and it is more useful than it looks, because it also lists the checks to clear before you blame the code.
Source: https://en.help.roblox.com/hc/en-us/art ... rror-Codes
Requirements to check first
The article opens with the conditions behind a large share of these errors:
- Internet speed of 4-8 Mb/s or above, plus the minimum system requirements for computers and for mobile devices.
- Mobile devices that are not on the original, updated operating system are not supported by Roblox.
- Virtual machines and cloud-based computers are not supported.
- Third party applications, including antivirus software, can conflict with Roblox and are worth checking.
If any of those describe your setup, that is the problem before any error code is.
The codes with their own page
Roblox documents these one by one:
- 264: same account launched an experience from different devices
- 266
- 267
- 268
- 270
- 277
- 279 / ID 17: failed to connect to the game
- 280
- 403: access to www.roblox.com has been denied, you are not authorized to view this page
- 524
- 600
- Failed to Load Library
Each of those links to its own article with the suggested steps. The index also says plainly that if your code or message is not listed, you should contact Roblox support, because there is no published article to follow.
The one people misread
Error 264 is not a connection fault. Roblox lists it as the same account launching an experience from different devices, so it points at a second session rather than a broken network. Error 279 / ID 17 is the opposite case: that one really is a failed connection to the game. Both have their own article, and the two fixes are nothing alike.
Send what is not in the list
The index ends with the same instruction for everything it cannot answer: contact the support team. Give them the exact code or message as it appeared, since that string is what decides which article, if any, actually applies.