Migration from 11.5 to 12.0 Issue

Hi All

We have recently migrated from 11.5 to 12.0.3(Build 106),

The issue is , when we try to open the some of the transactions or templates for editing, or try to call these from web pages, we are getting error <USERNAME> is not assigned a role that can perform this task.even when <USERNAME> is having the admin role.

Please help.

Regards