Errors in DHIS2 Demo Site

Hallo DHIS2 Team,

I am trying to use the Standard Reports in the DHIS2 Demo, but 2 of them give me errors i.e. ANC Coverages This Year and ANC Visits This Year. I tried them yesterday as well, but was getting the same error. I am particularly interested in these because they use the Jasper Report with report table data source, which am in the process of learning how to use. Could you please help and correct these errors? Also, could you please direct me on where to find resources that will help me grasp how to use this particular report type “Jasper Report with report table data source”? All your assistance will be highly appreciated.

Kind Regards,