different pdf version issue

[Ma, Xiaohui (NIH/NLM/LHC) [C]]

I have a problem to index pdf files which are pdf version 1.5 or 1.6. There is 
no problem at all for me to index pdf files with version 1.4.

Here is the error I got:
<h2>HTTP ERROR: 500</h2><pre>org.apache.tika.exception.TikaException: 
Unexpected RuntimeException from org.apache.tika.parser.pdf.pdfpar...@44ffb2

Does anyone have this problem when you indexed pdf files? 

Thanks so much in advance,
Xiaohui