Beginning in Strategy 11.0, Strategy Intelligence Server does not use Strategy Messaging Services to handle the DSSErrors logging output from the Intelligence Server process and other processes by default. The use of Messaging Services for DSSErrors logging is now controlled by a feature flag and can be enabled or disabled as desired. If Messaging Services is not enabled for DSSErrors logging, the Intelligence Server and other processes will log directly to file logs as in Strategy versions 10.5 and earlier.
If desired, Messaging Services for DSSErrors may be enabled through a feature flag located in Strategy Web Preferences > Project Defaults. To enable it, set the feature status for 10. Sending Log to Messaging Services to On.

Additionally, for Messaging Services to be able to write to the DSSErrors.log file, the Intelligence Server Log Consumer service must be running. If Strategy processes were registered as services at the time of installation, the Log Consumer service may be started by running the command:
service Strategy consumer-iserverstart
/<MSTR_INSTALL>/IntelligenceServer/KafkaConsumer/KafkaConsumer.sh start