There is an issue with the values returned from a sub-report, I have defined two variables (A and B) in a main report that are filled with the returned values from the sub-report.
I display those two variables (A and B) in a Text Field in the main report and they are ok, they display the correct values, but when I create a third variable and sum the variables A and B into this one, it's NULL.
I'm not sure what is the problem, but I'm not doing any complex calculation at any level, infact the Expression of the variables A and B in the sub-report is as follow:
A = 10.0
B = 5.0
I'm attaching a zip file that contains the .jrxml and .jasper files that you can used to reproduce this issue.