I encountered an error and was not able to save my project:
Saving project to 'ttest.wpr'.
Saving layer 'Base'.
Saving layer 'montology'.
java.lang.ClassCastException: org.wandora.topicmap.undowrapper.UndoTopicMap cannot be cast to org.wandora.topicmap.database.DatabaseTopicMap
at org.wandora.topicmap.database.DatabaseTopicMapType.packageTopicMap(DatabaseTopicMapType.java:99)
at org.wandora.topicmap.layered.LayeredTopicMapType.packageTopicMap(LayeredTopicMapType.java:82)
at org.wandora.application.tools.project.SaveWandoraProject.execute(SaveWandoraProject.java:99)
at org.wandora.application.tools.AbstractWandoraTool.run(AbstractWandoraTool.java:209)
at java.lang.Thread.run(Unknown