OpenAPITools/openapi-generator · error · IllegalArgumentException

{opt}: Invalid value '{value}'. {description}

Error message

{opt}: Invalid value '{value}'. {description}

What it means

Error "{opt}: Invalid value '{value}'. {description}" thrown in OpenAPITools/openapi-generator.

Source

Thrown at modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AspNetServerCodegen.java:672

    }

    private void setCliOption(CliOption cliOption) throws IllegalArgumentException {
        if (additionalProperties.containsKey(cliOption.getOpt())) {
            // TODO Hack - not sure why the empty strings become boolean.
            Object obj = additionalProperties.get(cliOption.getOpt());
            if (!SchemaTypeUtil.BOOLEAN_TYPE.equals(cliOption.getType())) {
                if (obj instanceof Boolean) {
                    obj = "";
                    additionalProperties.put(cliOption.getOpt(), obj);
                }
            }
            cliOption.setOptValue(obj.toString());
        } else {
            additionalProperties.put(cliOption.getOpt(), cliOption.getOptValue());
        }
        if (cliOption.getOptValue() == null) {
            cliOption.setOptValue(cliOption.getDefault());
            throw new IllegalArgumentException(cliOption.getOpt() + ": Invalid value '" + additionalProperties.get(cliOption.getOpt()).toString() + "'" +
                    ". " + cliOption.getDescription());
        }
    }

    private void setClassModifier() {
        // Check for class modifier if not present set the default value.
        setCliOption(classModifier);
    }

    private void setOperationModifier() {
        setCliOption(operationModifier);

        // If operation modifier is abstract then dont generate any body
        if ("abstract".equals(operationModifier.getOptValue())) {
            generateBody = false;
            additionalProperties.put(GENERATE_BODY, generateBody);
            LOGGER.warn("operationModifier is {} so forcing generateBody to {}", operationModifier.getOptValue(), generateBody);
        } else if (additionalProperties.containsKey(GENERATE_BODY)) {

View on GitHub (pinned to fcec517be3)

Solutions

1. Correct the value of the named option to one of the values described in the message.

When it happens

Trigger: Thrown when an ASP.NET server generator option is given a value that fails validation; the option name, offending value, and expected description are included in the message. Correct the option value as described.

Common situations: See trigger scenarios.

AI-assisted analysis of OpenAPITools/openapi-generator@fcec517be3 (2026-08-22). Data as JSON: /api/errors/520830189af09ef9. Report an issue: GitHub.