Last afternoon I created a project and deployed the mobile backend started. I edited the client code and sucessfully did some data insertion.
Some time (hours) after
I found that after redeploy a new version is created, instead of reseting the default one. When selecting this new version as 'default' everything worked as expected.
Select instance as default at (Main / Version):
https://appengine.google.com/adminlogs?&app_id=
Check at:
https://.appspot.com/_ah/api/explorer