My machine is Windows 7 64 bit.
Trying to convert a simple HTML test file to PDF. I can get it to work with Prince 7.1 and work with Prince 8.1, but when I use Prince 9, the PDF comes back with the html string rather than the rendered content. It also has a ÿþ begin in the PDF file content.

I have tried to uninstall and reinstall. I have also tried via command line. Still having the problem.

Can you attach the HTML file and the generated PDF here?

Samples attached. For this example, I did a View Source of one the sample pages
http://www.princexml.com/samples/catalog/PrinceFurniture.html

1. Prince Furniture.htm‎ 14.6 kB ‎
   View Source from Prince Furnatue Example
2. Prince Furniture.pdf‎ 38.0 kB ‎
   PDF from that code

A little more research. I found the issue. When I View Source in IE 9 and then save that content to .htm, then the file doesn't work in Prince. If I create the .htm file from scratch and then copy-paste the content in, it works (sample attached). Only difference I see is that the file size of the working file (Prince Furniture Works.htm) is about 1/2 of the error file (Prince Furniture Error.htm) .

1. Prince Furniture Error.htm‎ 14.6 kB ‎
   From View Source
2. Prince Furniture Error.pdf‎ 38.9 kB
3. Prince Furniture Works.htm‎ 7.3 kB ‎
   Made .htm file using Windows Explorer
4. Prince Furniture Works.pdf‎ 50.9 kB

Right, the broken HTML is using UTF-16 encoding, which our new HTML5 parser does not support. We highly recommend using UTF-8 instead, as UTF-16 just makes documents twice as big (7kb -> 14kb) and provides no benefits.