title: Train tesseract stopped working
body: <p>I'm using Serak Tesseract Trainer for Tesseract 3.0x. I added a Train Image, which then came from jTessBoxEditor (a Box Generator). When I pressed Train Tesseract, a DOS command prompts me, it's like training the image, then suddenly this appeared:</p>
  
  <p><strong>Reading dos.bookmanoldstyle.exp0.tr ... Font id = -1/0, class id =       1/42 on sample 0 font_id >= 0 &amp;&amp; font_id &lt;       font_id_map_.SparseSize():Error:Assert failed:in file       ....\classify\trainingsampleset.cpp, line 622</strong></p>
  
  <p>then a dialog box appeared that tells something about Shape clustering that has stopped working.</p>
  
  <p>I don't know what went wrong, the first time I used this, it worked fine though. Anyone who can help me resolve this?</p>