The training logbook is required to be left in its default state. Editing this logbook will cause this issue to occur.
If you have experienced this, check your logbook template within Settings and make sure no changes have been made.
If you have not edited the logbook template and have experienced this issue, raise a case and confirm the following details:
Who you are trying to bulk update the data for.
A screenshot of the issue.
Confirm if this occurs for all employees or just for specific employees.