Something I found that I had to do to get this library to work was to create an "hocr" configuration file for the Tesseract call.
It was throwing a "file not found" exception in the ParseHOCR method - basically, the *.hocr.html files weren't being created by Tesseract.
The fix seemed to be creating a text file named "hocr" (no extension) in the \bin\Debug directory of my project. The file contains a single line:
I'm not sure that this is the same config file the original developer was using, but it seems to be working-ish.