Hi, I have this really confusing issue where the log file is created, but empty. Below is the configuration I'm using (which is almost exactly the one given in the logback manual in the section on file appenders). Any help or suggestions on how to debug this would be much appreciated. Donald <configuration> <timestamp key="bySecond" datePattern="yyyyMMdd'T'HHmmss"/> <appender name="FILE" class="ch.qos.logback.core.FileAppender"> <file>UnitTest-${bySecond}.log</file> <append>true</append> <!-- set immediateFlush to false for much higher logging throughput --> <immediateFlush>true</immediateFlush> <!-- encoders are assigned the type ch.qos.logback.classic.encoder.PatternLayoutEncoder by default --> <encoder> <pattern>%-4relative [%thread] %-5level %logger{35} - %msg%n</pattern> </encoder> </appender> <root level="TRACE"> <appender-ref ref="FILE" /> </root> </configuration>