Error
In Club Penguin, an error is typically an orange box that shows up on a client's screen in the form of a notification typically containing a single 'Ok' button that allows the client to close the error, or redirect themselves to a help page.
Example
An example of an error is when attempting to log in with an incorrect password. The packet for this error is %xt%e%-1%101%. You can see the error code in the corner of the orange box given when you receive an error.