Simple-search Internal server error?

[PANYARAK NGAMSRITRAGUL]

Hi,

My institution is running a DSpace 5.5 instance, recently it generates a lot of internal server errors.  Most of them caused by crawling of search engines.

I have been trying to solve this problem by:

1. disallow crawling from search engine.

2. install a similar DSpace instance in new server.

But still cannot find out the root cause of the problem.

Today, I figured out the if I stripped the "filtertype=equals" out, the link works just fine, e.g. the request from this link

http://kb.psu.ac.th/psukb/handle/2553/1184/simple-search?filterquery=2550&filtertype=equals

will generate an internal server error with the error message as attached.

If I stripped out the "&filtertype=equals", the link works just fine.

Can someone help me to solve this problem?  Thank you.

Panyarak Ngamsritragul

Prince of Songkla University