For upgrade from 5.6 to 5.7 then over, I just followed this guide: Tutorial upgrade from 5.6 to 5.7
All perfect until when I click on the “Export Batch” in the Concrete5 184.108.40.206.
The add-on migration tool legacy broke with this message:
Fatal error: Call to a member function getValue() on null in ./concrete/core/libraries/attribute/controller.php on line 46
Migration Tool (0.9.8)
Cache Settings: Off
If someone solve, there is the ISSUE in GitHub: GitHub ISSUE
Thank you in advance.