sorry for the delayed answer.
I just tried OS 8.6 which didn't resolve the issue. Error -43 is still being shown when I try to install the database.
Where do you run the installer and where to do you try to install? (where = which volume, which location)
I run the installer from my MacOS volume in SheepShaver which i created with SheepShaver itself (size 2 GiB, assorted RAM for MacOS is 1 GiB) and i want to install it just there. The database seems to be a self-extracting file as it opens Stuffit as far as i can see.