Unable to deploy an application module on AppEngine

Question

I am unable to deploy an application module.

 appcfg.py update --oauth2 app.yaml producer.yaml

Error 409: --- begin server output ---
Another transaction by user rue1401 is already in progress for app:     s~lpsng2, version: 4. That user can undo the transaction with "appcfg rollback".
--- end server output ---

Doing an

appcfg.py rollback . --oauth2 app.yaml producer.yaml

indicates no error, but does not solve the problem.

Deploying the default modules (for the same application) works.

Answer 1

Incrementing the version (in the .yaml files), redeploying both modules, and activating the new version finally solved the problem.