Fatal error: Call to a member function getValue()

[ecoecoe]

I just tried to export data from Concrete5 version 5.6.4, when I click on "Export Batch" it stop to work for this problem:
Fatal error: Call to a member function getValue() on null in ./concrete/core/libraries/attribute/controller.php on line 46

Thanks in advance

[ecoecoe]

I solved this problem, and it seem to be all correct by comment that function in that lines, so the export process worked. It is only a trick, not the solution.