Error with subdescriptor

Field testing was an elementary
and create an subdescriptor for the same,
but he begins to give an error.

I know I may not have performed the task correctly
but close the workbench
I think it should not.

I create AA and after create AB and when i click “define” display error.

Exactly, it should not, this looks like an error in the DBA workbench.

you know who
these images error
for Solution
for future versions?