I had this error too on the Windows machine.
My solution.
1) Download your language files from https://github.com/tesseract-ocr/tessdata/tree/3.04.00
For example, for eng, I downloaded all files with eng prefix.
2) Put them into tessdata directory inside of some folder. Add this folder into System Path variables as TESSDATA_PREFIX.
Result will be System env var: TESSDATA_PREFIX=D:/Java/OCR And OCR folder has tessdata with languages files.
This is a screenshot of the directory: