Well, we're close - I think...
The most likely issue is that one of the subreports is getting a dataset that it does not understand. E.g.; it's format is different than what it expects. To troubleshoot this:
1) Back up the report
2) Delete one subreport.
3) Save.
4) Alter your code to reflect the removal of the subreport.
5) Run the app.
Repeat the above until you get the app working. Then saved out the problem subreport and run it in a new test app as a main report, passing it the dataset and following the troubleshooting steps in the following wiki:
- Ludek