I tried to respond to a comment on my CommentLuv plugin page this morning, and I was greeted with this error,
500 Error — Internal Server Error. There has been an internal server error
oh noes!! The site was working fine for the main index page but single posts kept on throwing up a 500 error

I had a quick search of the WordPress forums and found a variety of posts from people experiencing the same problem, each one with a different solution. I went through each solution until I revived the site back to it’s normal functionality.. here’s what I did..

1. .htaccess
   Some people had the problem because their htaccess file was not writable or their server had mod_rewrite disabled. I tried deleting the htaccess file and then going back to ‘options/permalinks’ and updating the permalink structure. The update went through with no problems (sometimes it will say “could not update htaccess” which means it is not writable by the server). The problem still persisted though..
2. wp-cache
   I thought it might be a cache problem seeing as the CommentLuv page gets so many visitors (it has a pr5 too!), I disabled the cache plugin.
   still no joy…
3. php.ini – only 8m of memory?
   I thought it might be too much memory used (I was close) so I edited php.ini in the root of my hosting folder and put this line in.
   memory_limit=16M
   Not successful
4. Too much content?
   I tried browsing to the CommentLuv page on my mobile phone once and it crashed with “out of memory” error and considering it has (atm) 199 responses, I thought that might be something to do with it. I know my stats sometimes give me a 500 internal server error when it takes a long time to load so that looked to be the problem.
   I downloaded a plugin called ‘paged-comments‘ and installed it, I particularly like the way you can stop it from paging every post and only choose which posts need paged comments by adding a custom field to the post editing screen.

   Sorted that out and tried to view the page, it loaded partly! almost there!

5. Plugin memory hog.
   On the nearly loaded page there was an out of memory error relating to sh-autolink (a plugin which automatically makes certain words in to html links) so I disabled that and SUCCESS!
   It all works fine now.

A combination of too many comments and a plugin that scans the whole text for keywords led to my 500 internal server error for WordPress, it’s now fixed with a neat plugin and a quick removal of another. phew!

The CommentLuv plugin page is now up and working fine again, I never realized that it would get so much attention when I first drafted it. Thanks everyone for using CommentLuv!