This message is generated if the value of the CharacterEncoding option is neither a string nor a list of the indicated form.
This message can also be generated by an attempt to assign to $CharacterEncoding a value which is neither a string nor a list of the indicated form.
Some of the valid values for $CharacterEncoding can be found by looking at the names of the files in the SystemFiles/CharacterEncodings directory for your copy of the Wolfram System.
Off[message] switches off the message; On[message] switches it on. For example: Off[$CharacterEncoding::charcode].
Examples
Basic Examples(1)
The list {1,1} does not have the correct form to be used as a value of $CharacterEncoding: