With logback configured to scan for changes in the config file, if the change causes an error in the configuration (e.g. syntax of undefined property) the logger remains unconfigured and does not perform any future scans. The only way to reconfigure the logger is to restart the applicaiton (in the case of a webapp).

It would be good for logback to be able to recover from such an error by reverting to the previous configuration so that logging continues and also the error in the config file may be fixed.