The error message There was an error retrieving data "Cannot read property 'fullName' of undefined" will pop up while opening a calibration session.
Reproducing the Issue
Proxy as the affected User - Calibration - Click on the session - Error message is displayed.
Configuration Issue. Permission is not granted to the user.
The user is not granted the 'user search permission' under RBP.
Log in as super admin and give the permission to everyone. The permission is under General User Permission-?Company Info Access.
When you finish granting it , please try opening the session , remember not to restrict target for owner in calibration template.
The user search permission is not specific for calibration. It's platform RBP's required permission. Without this permission, you are not able to get user's information, which makes the calibration session not getting the users when you open session.
For opening a calibration session, the minimum permission is the role has "Read" permission, which is configured in Manage Calibration Setting.
KBA , LOD-SF-PM-CAL , PM-Calibration Issues Specific to PM Forms , Problem