Upgrade from 2.4.6 to 3.1.1 article name dont show and getFullName() function return 0 item

[samarabbani]

hi evryone,
after update from ojs 2.4.6 to ojs 3.1.1, authors dont show in inedxournal and in article_details pages, and getFullName() result is empty.
how to fix this problem?