What is the issue?
PDF/UA > Logical Structure > Role mapping > Role mapping of standard structure types > Structure type 0 is mapped in a circular fashion
What does it mean?
There is a Standard structure type that is remapped to the same standard structure type - according to PDF/UA this is not allowed.
How to fix it?
Go to the ribbon tab Logical Structure in axesPDF and use the tool Fix Roles. Delete the mapping of the Standard structure type by clicking the cross.