Welcome to our forums!
While the Viewer is no longer for sale, not being actively developed - we would still be happy to assist anyone who has questions about it. We also normally reply within the hour of receiving a support request if it came in during office hours.
Help is also available - and the complete Viewer documentation is available along the documentation of all our other products here:http://help.tracker-software.com/
We also have an extensive KB article system which complements the above:https://www.tracker-software.com/knowledgebase
As for your actual question - I had a copy of the portable Viewer on my machine that was missing the ocrdats folder and as such was not showing any available languages for OCR. I added that folder manually - and then copied the OCR language files from the installed copy of the Editor - and it worked - please check the attached images.
The link at the start of this topic takes you to the SDK version of the OCR files - as at the time I posted that link - we didn't have this one:https://www.tracker-software.com/pdf-xchange-viewer-ocr
Which allows you to download and install the OCR languages for our end user products.
If you still want to manually create the .lng files as described earlier in this topic - the contents of those files is:
<?xml version="1.0" encoding="utf-8"?>
<language name="Bengali" prefix="ben" version="1.00"/>
Where you need to update the name to the correct language, and the prefix is the three letters from the name of the actual OCR file (e.g. ben
_pxvocr.dat in the case of Bengali).