Hi Susan,
I think you can delete records in the role_capabilities table even if they exist in the context table, because this capability no longer exists in moodle from 3.1, anyway this capability will not be used in the context association, you should not delete the records from the table context because this can refer to some module or course.
In our case those contexts no longer existed, maybe module or course had been deleted.
Regards
Yerko Zúñiga
Mindfree Ingeniería
I think you can delete records in the role_capabilities table even if they exist in the context table, because this capability no longer exists in moodle from 3.1, anyway this capability will not be used in the context association, you should not delete the records from the table context because this can refer to some module or course.
In our case those contexts no longer existed, maybe module or course had been deleted.
Regards
Yerko Zúñiga
Mindfree Ingeniería