Camunda Parallel Gateway - token lost

Hi everyone,

I have a production bug in my Camunda process containing parallel gateway.
I have followed all of the instructions, but the problem occurs if the bottom part of the process get executed immediately (leaving with No branch of execution).
The bottom token then disappears - in history tables the gateways from bottom part are missing. The upper one then gets stuck at parallel gateway marked with red color. I marked with yellow where the tokens should have traveled.
This has actually happened during process migration - because parallel task did not exist at the time. Unfortunately, the migration did not report an error in this case.

I now understand what happened but need help fixing it - the process must proceed.

This might be unrelated but why do you have a mark on the flow from the “x” to the “+”?

If you mean the default mark, it is so the gateway won’t show error for not having default branch, otherwise it would require a condition

Hello @JuLog ,

could you please upload the BPMN file?

Plus, optimal would be a junit test that leads to the behaviour. But this is not required.


Of course, I simplified it as much as I could for the purpose of clarifying the issue.
sampleBefore.bpmn (6.1 KB)
sampleAfter.bpmn (13.9 KB)

So the before sample represents first version of the process which I migrated to second version, resulting in processes being in “Task upper” during the migration to be stuck on parallel gateway after the task is completed (since it “waits” for other token which is not present and could not be). I hope I managed to explain the issue. I assume some sort of migration has to be done, but not sure on the actual way to do it.

Hello @JuLog ,

this sounds to me like you did a migration before the problem appeared?

If yes, where did you migrate tokens from and to?