The follwoing logback.xml works with tomcat, but not in orion application server: <?xml version="1.0" encoding="UTF-8" ?> <configuration> <appender name="ROLLFILE" class="ch.qos.logback.core.rolling.RollingFileAppender"> <file>${LOG_HOME}xsvapp.log</file> <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy"> <param name="FileNamePattern" value="${LOG_HOME}xsvapp.log.%d{yyyy-MM-dd}" /> </rollingPolicy> <layout class="ch.qos.logback.classic.PatternLayout"> <param name="Pattern" value="%d{HH:mm:ss} %-5level [%thread] %class{25} - %msg%n" /> </layout> </appender> <root> <level value="debug" /> <appender-ref ref="ROLLFILE" /> </root> </configuration> I get the following NPE: 04.05.07 11:00 ixmidixservweb: Error initializing servlet java.lang.ExceptionInInitializerError at com.ixmid.ixservweb.web.session.SmnResolveProxies.<clinit>(SmnResolveProxies.java:117) at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Class.java:247) at com.evermind._ay._lse(Unknown Source) at com.evermind._ay._cbd(Unknown Source) at com.evermind._ay._lze(Unknown Source) at com.evermind._ay._lme(Unknown Source) at com.evermind._ay.<init>(Unknown Source) at com.evermind._am._rvb(Unknown Source) at com.evermind._ex._rvb(Unknown Source) at com.evermind._eu._kie(Unknown Source) at com.evermind._eu._bi(Unknown Source) at com.evermind._ex._bn(Unknown Source) at com.evermind._ex._bi(Unknown Source) at com.evermind.server.ApplicationServer._gse(Unknown Source) at com.evermind.server.ApplicationServer._bi(Unknown Source) at com.evermind._csb.run(Unknown Source) at java.lang.Thread.run(Thread.java:619) at com.evermind._bf.run(Unknown Source) Caused by: java.lang.NullPointerException at ch.qos.logback.core.util.PropertySetter.computeContainmentTpye(PropertySetter.java:234) at ch.qos.logback.core.util.PropertySetter.canContainComponent(PropertySetter.java:207) at ch.qos.logback.core.joran.action.NestedComponentIA.isApplicable(NestedComponentIA.java:57) at ch.qos.logback.core.joran.spi.Interpreter.lookupImplicitAction(Interpreter.java:214) at ch.qos.logback.core.joran.spi.Interpreter.getApplicableActionList(Interpreter.java:233) at ch.qos.logback.core.joran.spi.Interpreter.startElement(Interpreter.java:122) at ch.qos.logback.core.joran.spi.Interpreter.startElement(Interpreter.java:110) at ch.qos.logback.core.joran.spi.EventPlayer.play(EventPlayer.java:36) at ch.qos.logback.core.joran.spi.Interpreter.play(Interpreter.java:336) at ch.qos.logback.core.joran.GenericConfigurator.doConfigure(GenericConfigurator.java:96) at ch.qos.logback.core.joran.GenericConfigurator.doConfigure(GenericConfigurator.java:74) at ch.qos.logback.core.joran.GenericConfigurator.doConfigure(GenericConfigurator.java:38) at com.ixmid.bas.BasLog4j.<clinit>(BasLog4j.java:68) ... 19 more any idea? (the "normal" FileAppender works with both tomcat and orion) -- View this message in context: http://www.nabble.com/NullPointer-in-PropertySetter.computeContainmentTpye-t... Sent from the Logback User mailing list archive at Nabble.com.