This Bugzilla instance is a read-only archive of historic NetBeans bug reports. To report a bug in NetBeans please follow the project's instructions for reporting issues.
slf4j is fairly popular around here and my hints the IDE are of no use because they only handle java util logging. I've workarounded the problem by Find&replace "import org.slf4j.Logger" with "import java.util.logging.Logger", performing the "String concatenation in logger" via Inspect&Transform, then reverting the import statement changes, Find&Replace for "logger.log(Level.INFO" -> "logger.info(" and them manually replacing {0} with {} etc. There should be a better way.