I have a simple report with one table in a report container.
I right click on that table - and select Append a Sub Element
I then select SubReport
I then select one of the reports that I have attached to that report and click OK.
Then nothing happens, I can not click on anything in the designer.
Unfortunately, we were not able to reproduce the behavior on our end. For this reason we would ask you to open a case in the support center and send us a dump file of the designer. How to create a dump file can be found here:
If you have any further questions, please do not hesitate to contact us.