org.xwiki.platform%3Axwiki-platform-workspace-api extension breaks upgrade to 4.4.1

Ubuntu 12.04 64 bit root@wiki01-smart :/var/lib/xwiki/extension# dpkg -l | egrep 'mysql|jdk|tomcat|xwiki' ii libdbd-mysql-perl 4.020-1build2 Perl5 database interface to the MySQL database ii libmysql-java 5.1.16-2 Java database (JDBC) driver for MySQL ii libmysqlclient18 5.5.29-0ubuntu0.12.04.1 MySQL database client library ii libtomcat7-java 7.0.26-1ubuntu1.1 Servlet and JSP engine -- core libraries ii mysql-client-5.5 5.5.29-0ubuntu0.12.04.1 MySQL database client binaries ii mysql-client-core-5.5 5.5.29-0ubuntu0.12.04.1 MySQL database core client binaries ii mysql-common 5.5.29-0ubuntu0.12.04.1 MySQL database common files, e.g. /etc/mysql/my.cnf ii mysql-server 5.5.29-0ubuntu0.12.04.1 MySQL database server (metapackage depending on the latest version) ii mysql-server-5.5 5.5.29-0ubuntu0.12.04.1 MySQL database server binaries and system database setup ii mysql-server-core-5.5 5.5.29-0ubuntu0.12.04.1 MySQL database server binaries ii mysqltuner 1.1.0 high-performance MySQL tuning script ii openjdk-7-jdk 7u9-2.3.4-0ubuntu1.12.04.1 OpenJDK Development Kit (JDK) ii openjdk-7-jre 7u9-2.3.4-0ubuntu1.12.04.1 OpenJDK Java runtime, using Hotspot JIT ii openjdk-7-jre-headless 7u9-2.3.4-0ubuntu1.12.04.1 OpenJDK Java runtime, using Hotspot JIT (headless) ii openjdk-7-jre-lib 7u9-2.3.4-0ubuntu1.12.04.1 OpenJDK Java runtime (architecture independent libraries) ii php5-mysql 5.3.10-1ubuntu3.5 MySQL module for php5 ii tomcat7 7.0.26-1ubuntu1.1 Servlet and JSP engine ii tomcat7-admin 7.0.26-1ubuntu1.1 Servlet and JSP engine -- admin web applications ii tomcat7-common 7.0.26-1ubuntu1.1 Servlet and JSP engine -- common files ii xwiki-enterprise-common 4.4.1 XWiki enterprise common package ii xwiki-enterprise-mysql-common 4.4.1 XWiki enterprise MySQL common package ii xwiki-enterprise-tomcat-common 4.4.1 XWiki enterprise Tomcat common package ii xwiki-enterprise-tomcat7-mysql 4.4.1 XWiki enterprise Tomcat/MySQL based package