Hi,
after several days of tinkering with version 3, we got Milestones to work by:
1. persisting MilestoneInstance, MilestoneNode
2. changing jbpm.varmapping.properties order of bottom lines:
{hibernateable-long-id-classes} org.jbpm.context.exe.variableinstance.HibernateLongInstance {hibernateable-string-id-classes} org.jbpm.context.exe.variableinstance.HibernateStringInstance {serializable-classes} org.jbpm.context.exe.converter.SerializableToByteArrayConverter org.jbpm.context.exe.variableinstance.ByteArrayInstance
if you use the search functionality and limit the search to this forum, you can find answers rather quickly (provided an answer is there)