migrate field instance table

hi there i amfessing the issue while migrate from d6 (old site having data also) to new d8 fresh installed site.
on upgrade_d6_field_instance_widget_settings there nothing is imported.
when by drush command i have checked the status it says like that

8b3319f86c8d38ebf6dd1015209fc35f17789bad3c5562bb5bf3c55f4485c7b8 1 Input should be an array.

but unable to debug it future.
Please, some body help me to resolve this issue.