unsupported_value

The value '{0}' isn't supported by '{1}'.

The analyzer produces this diagnostic when an analysis options file contains a valid option and the value of that option is not a valid value.

The following code produces this diagnostic because fatal isn't a valid severity:

// %uri="analysis_options.yaml"
analyzer:
  errors:
    dead_code: fatal

If a valid value specifies the intended behavior, then replace the unsupported value with it:

// %uri="analysis_options.yaml"
analyzer:
  errors:
    dead_code: error

If there is no valid value to use, then remove the option:

// %uri="analysis_options.yaml"
analyzer:
  errors: