Setting data field "cyrname" to undefined is invalid.

The error message you mentioned, "Setting data field 'cyrname' to undefined is invalid," suggests that you are attempting to set the value of the data field 'cyrname' to 'undefined', which is not a valid value.

In JavaScript, 'undefined' is a special value that represents the absence of a value. When setting a data field, you should assign a valid value to it, such as a string, number, boolean, object, or null.

To fix the error, make sure you are assigning a valid value to the 'cyrname' field. For example:

data: {
  cyrname: "John Doe" // Assigning a valid value
}

If you need further assistance, please provide more context or code snippets related to the issue you are facing.