If this are PDF files then Firefox should be able to show them in a Firefox tab using the builtin PDF Viewer. Previously you needed to use a plugin to show the TIFF files, but current releases no longer supports plugins other than Flash.

Can you post a link to a publicly accessible page (i.e. no authentication or signing on required)?

The built in PDF viewer does not work here. It works with other PDFs.

Still need help. Thanks.

Can you post a link to a publicly accessible page (i.e. no authentication or signing on required) like I asked above?

It was years ago when I last saw a question above this office.