Comment 3 for bug 1232258

This bug also happen on Ubuntu Server 14.04 using package tomcat7-user .

References to those folders are in this file : conf/catalina.properties (in the tomcat instance) :

common.loader=${catalina.base}/lib,${catalina.base}/lib/*.jar,${catalina.home}/lib,${catalina.home}/lib/*.jar,${catalina.home}/common/classes,${catalina.home}/common/*.jar
server.loader=${catalina.home}/server/classes,${catalina.home}/server/*.jar
shared.loader=${catalina.home}/shared/classes,${catalina.home}/shared/*.jar

Content of those folders appear to be optional

$catalina.home is defined in : bin/setenv.sh (in the tomcat instance)

So I created those folders :
sudo mkdir -p /usr/share/tomcat7/common/classes
sudo mkdir -p /usr/share/tomcat7/server/classes
sudo mkdir -p /usr/share/tomcat7/shared/classes