In some instances, you might need to adjust the permissions on the PolicyBanner file.

For .txt or .rtf files, set the permissions on the Policy Banner file so that Everyone (Other) has read privileges:

sudo chmod o+r /Library/Security/PolicyBanner.txt

sudo chmod o+r /Library/Security/PolicyBanner.rtf

For .rtfd files, adjust the permissions so Everyone (Other) has both read and execute privileges:

sudo chmod -R o+rx /Library/Security/PolicyBanner.rtfd