After upgrading Oracle Forms and Reports from a previous version (e.g. 10g or 11g) to 12c, there is a known issue where running Oracle Reports in 12c with the RUN_REPORT_OBJECT built-in causes the following error:
“FRM-41214: Unable to run report”
Starting in Forms 12c, a new environment variable, CONFIGURE_COMPONENT_PATH, has been created. This should be placed in your environment file (.env) used by your Forms application. The variable should be mapped to the location of your ReportsToolsComponent. You may either edit the file manually or create a new variable under Environment Configuration for the Forms instance in EM FMW Control.
NOTE: If you use EM FMW Control to create or modify your environment variables for Forms, it is highly recommended to continue to use EM FMW Control.
In addition, make sure that the CLASSPATH variable has the full path to rwrun.jar (%ORACLE_HOME%\reports\jlib\rwrun.jar), as this jar file is required to generate reports from Oracle Forms.
After you have made the changes, re-launch the Forms application. You should now be able to run a report.
Source: Oracle Support note 2074841.1