Troubleshooting reportingEdit online If you have problems with Cognos Analytics, check the troubleshooting information. Polled data reports contain null valuesIf reports on polled data contain null values, you might need to clear the polling data.Changing the logging level for reportingFor information on how to set logging and on how to change the logging level for Cognos Analytics, see the Cognos Analytics Knowledge Center at https://www.ibm.com/support/knowledgecenter/SSEP7J.Parent topic: Troubleshooting Network Manager