I modeled a process with a sub process in it.
Inside this sub process I have a Service Task.
The sub process runs on a no sequential loop.
The service task is asynchronous.
I got the following exception :
Exception in thread "pool-1-thread-11" org.activiti.engine.ActivitiOptimisticLockingException: VariableInstanceEntity was updated by another transaction
The process retries the Service Task in error.
Please find the project and a JUnit test in attachment.
Windows XP, Eclipse 3.6, Java 6.