private void warnAuthAborted() {
        String identifier = getIdentifier();
        logger.warn("The \"{}\" authentication provider has encountered an "
                + "internal error which will halt the authentication "
                + "process. If this is unexpected or you are the developer of "
                + "this authentication provider, you may wish to enable "
                + "debug-level logging. If this is expected and you wish to "
                + "ignore such failures in the future, please set \"{}: {}\" "
                + "within your guacamole.properties.",
                identifier, ExtensionModule.SKIP_IF_UNAVAILABLE.getName(),
                identifier);
    }
Logs a warning that the authentication process will be entirely aborted
due to an internal error, advising the administrator to set the
"skip-if-unavailable" property if error encountered is expected and
should be tolerated.
guacamole/src/main/java/org/apache/guacamole/extension/AuthenticationProviderFacade.java