15-Nov-2019 16:25:56.511 INFO [Catalina-utility-1] org.camunda.commons.logging.BaseLogger.logInfo ENGINE-08023 Deployment summary for process archive ‘SimpleDemo’:
15-Nov-2019 16:25:56.646 SEVERE [Catalina-utility-1] org.camunda.commons.logging.BaseLogger.logError ENGINE-16004 Exception while closing command context: The deployment contains definitions with the same key ‘SimpleDemo1’ (id attribute), this is not allowed
org.camunda.bpm.engine.ProcessEngineException: The deployment contains definitions with the same key ‘SimpleDemo1’ (id attribute), this is not allowed
This error can occur if you have another bpmn file with the same key “SimpleDemo1”. The key is mapped to “Id” field in Modeler. So, basically you can check if there exists any other bpmn with the same Id as “SimpleDemo1”. If yes, then you would have to change the “Id” of that bpmn.
Basically, you can not have bpmn files with same key ( Id field in Modeler or “id” attribute in bpmn file) in same deployment.