Getting a 500 Error on Certain PHP Pages via GoogleBot Only

Question

I recently noticed that one of my websites (the site is a self-hosted Wordpress site) was no longer showing up in Google. I used the Google Webmaster tools to find out that the googlebot was getting server error 500 on a number of pages. For example:

http://johnkivus.com/
http://johnkivus.com/2010/01/22/center-of-my-world/
http://johnkivus.com/2010/01/22/creative-outlet/
http://johnkivus.com/2010/01/22/sailing-sailing/

These pages all seem to load without error in my web browser. I have tried a few things (such as turning off caching) but since I cannot reproduce the error in my browser, I am not sure how best to go about debugging the problem. (I'm not a well-versed PHP programmer by any stretch.)

I have been using http://web-sniffer.net/ (in additional to the Google Webmaster tools) to see how Googlebot is viewing my pages. Unfortunately, it does not give a lot of good information to help me debug.

Any suggestions? Also, if I have left out a key piece of information (most likely out of ignorance) needed to answer this question, please let me know and I'll provide it.

Answer 1

I'm not sure if this is your particular issue, but a guy here has the exact same problem: http://wordpress.org/support/topic/500-errors-galore

"WP Security Scan" plugin causes the error it seems. Removing that plugin fixes it.

Answer 2

This used to happen to my from time to time, amongst getting other error codes, from Webmaster Tools.

Have you checked your server logs to see if there are any other instances of 500 errors being dished out?