Hi, For our tomcat (10.0.23) web application, we use an env-entry to specify the context name in the logback configuration file:     <insertFromJNDI env-entry-name="java:comp/env/loggingContextName" as="loggingContextName" />     <contextName>${loggingContextName}</contextName> This context name is also used in defining the log file name:     <appender name="ERRORFILE" class="ch.qos.logback.core.rolling.RollingFileAppender">         <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy"> <fileNamePattern>${logDir}/${loggingContextName}_error_%d{yyyy-MM-dd}.log             </fileNamePattern>             <maxHistory>7</maxHistory>         </rollingPolicy>         <encoder>             <pattern>%d{ISO8601} %5p [%X{session}] [%c]: %m%n</pattern>         </encoder>         <filter class="ch.qos.logback.classic.filter.ThresholdFilter">             <level>WARN</level>         </filter>     </appender> And in web.xml we define that environment entry:     <env-entry> <env-entry-name>loggingContextName</env-entry-name> <env-entry-type>java.lang.String</env-entry-type>         <env-entry-value>server_v4</env-entry-value>     </env-entry> This configuration is in accordance with https://logback.qos.ch/manual/configuration.html. Using logback-classic in version 1.2.11, the corresponding log information is written to the file server_v4_error_2022-11-09.log, as expected. However, after upgrading to logback-classic version 1.4.4 (or 1.3.4), the corresponding log information is written to a file loggingContextName_IS_UNDEFINED_error_2022-11-09.log, and tomcat prints the following to the console during startup: 14:11:58,019 |-ERROR in ch.qos.logback.core.model.processor.DefaultProcessor@1390cc4c - Can't handle model of type class ch.qos.logback.core.model.InsertFromJNDIModel  with tag: insertFromJNDI at line 5 What am I missing here? Many thanks Ove Hiltwein -- Ove Hiltwein @ Nebion AG (an Immunai company) / Zurich (CH) www.nebion.com -- PLEASE NOTE: The information contained in this message is privileged and confidential, and is intended only for the use of the individual to whom it is addressed and others who have been specifically authorized to receive it. If you are not the intended recipient, you are hereby notified that any dissemination, distribution, or copying of this communication is strictly prohibited. If you have received this communication in error, or if any problems occur with the transmission, please contact the sender.