Hi, i just started with iReport and downloaded iReport-3.7.2 and could generate a simple report and preview it. Was allright. Then i tried to start this report in Oracle APEX and got the same Error Message as ivanyiu. As he worked out there may be an incompatibility between iReport 3.7.2 and the corresponding Jasper Report library. But i can not revert back to 3.7.1. I didn't find a way to upgrade Jasper Report. Can anybody help me? Michael