1, Copy the "Help_WebPortal_EN.zip" from the 8.1.2 installation media to the path shown in the error, creating folder:
2. Rename the .zip file to "OneIM_QER_WebPortalUserGuide.zip"
The "Add Help Archive" button will now work as expected.
A hotfix is available from Support. Please contact Support, provide the affected version of Identity Manager and quote Solution ID 322462.