I'm also having errors in calling a report using the following code:
:SYSTEM.MESSAGE_LEVEL := 5;
RID := FIND_REPORT_OBJECT('cakes');
RNAME := RUN_REPORT_OBJECT(RID);
:SYSTEM.MESSAGE_LEVEL := 0;
I'm now at a different computer which has no Oracle package downloaded, so the errors were shown in 2 alert boxes, first says that the run_report_object couldn't be called, and the second telling something about 1 argument (sorry for my embeguice errorsm this is what I could remember)
considering that I had called a report before from the same computer.