After the conversion of the input TIFF document into PDF, each page duplicated with its small thumbnail.

It happens when each original TIFF image contains 2 pages with a different resolution. At the same time, FineReader recognizes and converts all pages from the input TIFF document. Thus, the issue does not connect to the FineReader program.

In this case we recommend you to rescan the document into a different image format or try to scan directly into FineReader program using the option "Scan to PDF".