Copy this dll in again to the Infusion folder, after deleting the existing one.
Restart the computer and reinstall the workstation or data file. If the error persists manually register the file.
Alternatively, the 2 .dll files may need to be added to the DATA folder this is where the tnimp.exe file is stored.
Just copy and paste, they do not need to be registered.
This may be required to operate the Contract Rate Import Utility