[Oreka-user] Error deploying web application directory orkweb/orktrack

Hello,
I couldn't start orkweb and orktrack after installing from script. How can I correct these errors?

org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/orkweb]]
Caused by: java.lang.NoClassDefFoundError: Lorg/apache/log4j/Logger;
Caused by: java.lang.ClassNotFoundException: org.apache.log4j.Logger
SEVERE: Error deploying web application directory /opt/tomcat7/webapps/orkweb

org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/orktrack]]
Caused by: java.lang.NoClassDefFoundError: Lorg/apache/log4j/Logger;
Caused by: java.lang.ClassNotFoundException: org.apache.log4j.Logger
SEVERE: Error deploying web application directory /opt/tomcat7/webapps/orktrack

Thank you,
Miko