An error happens when the player fails to access a level in Web version (usually happens due to a poor internet connection). When the "ok!" button is pressed, the level will not be loaded, forcing the player to refresh the page.
Sometimes, multiple error messages will be displayed (the number below the error message displays the number of error messages that will appear), which when the "ok!" button is clicked, another error message will pop up until all the error messages have appeared.
The player can copy all or part of the error message shown.
Rarely, the error message can also appear while in the game, though the player is allowed to continue as normal.
If it happens when you completed a level, the level will not be recorded when you refresh, you will unfortunately lose a life, and you have to do it all over again. Similarly, if it was done on a level that was already completed and you get a higher score than you used to had, the new score will also not be recorded. It is very frustrating, especially if it was a hard level in which you had a high score or if the level was extremely hard to get three stars when the user had three stars.
To see the reason why the game is error, copy link in error notification and insert new tab.