In the messages.properties file there are strings defined that are intended to over ride the default values JSF conversion and validation error messages: > javax.faces.converter.BigDecimalConverter.DECIMAL > > ... > > javax.faces.validator.LongRangeValidator.TYPE These appear to not be used because if I have (say) an integer where JSF rejects the non-integer value being set the error message shown is in the format of the default message: > javax.faces.converter.IntegerConverter.INTEGER={2}: ''{0}'' must be a number consisting of one or more digits. When it should be in the format defined in messages.properties: > javax.faces.converter.IntegerConverter.INTEGER=value must be an integer The solution is that faces-config.xml requires the following in order to over ride the default values: ``` <message-bundle> messages </message-bundle> ``` See: https://stackoverflow.com/questions/2668161/internationalization-in-jsf-when-to-use-message-bundle-and-resource-bundle