Please explain what you mean. Is it the case that you get an error, does nothing happen, does a server crash? Provide the details.
Also, there are post configuration steps required for Reports. Did you complete those? They are explained in the Installation Guide. You must create the Reports Tools Components. See section 126.96.36.199 https://docs.oracle.com/middleware/12213/formsandreports/install-fnr/installing-and-configuring-oracle-forms-and-reports1.htm#FRINS-GUID-4BB984E2-52A6-4C62-A735-D160CAC1F653
Once all servers are configured and running, you must set a new Forms environment variable. This is explained here:
Hi, 0b4f... would you mind changing your profile so that we could call your user shortname? Michael provided good pointers in your infrastructure, We would need additional information to help you out, are you trying to launch a report from Forms using a run_report_object if yes here is something that might point you in the right direction. https://www.oracle.com/technetwork/developer-tools/forms/documentation/formsreportsintegration-12c-3014203.pdf
Have a nice day.