I recently noticed an issue on this very blog and a couple i have hosted on this server when people just hit submit on the comment form without entering anything into the comment field- i would get a 500 server error back.

I spent ages googling figuring it was some kind of config error on the server as it happened across all of the wordpress blogs on this server- I eventually found it wasn’t an error at all- The skins used across these blogs didn’t seem to validate the forms so it was falling back to wordpress which was returning an error like “Error: please type a comment.”- however IIS seemed to be intercepting this as a full error and rendering a 500 error- the solution was simple!  Turn on detailed error’s.  Obviously this isn’t good on a production box running dot net, but for PHP you can control the error reporting from within the php.ini file anyway, so this just makes sure IIS doesn’t add an additional layer of error filtering confusing matters.

Update: Thanks to Kanwaljeet Singla on the comments for pointing out a better fix for this as detailed on Kern Handa’s blog here.  This can basically be fixed easily by setting a web config entry to tell IIS to let errors pass through, like so;

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <system.webServer>
        <httpErrors existingResponse="PassThrough" />
    </system.webServer>
</configuration>

I recently rebuilt a Windows 2008 server and set it up with PHP5 and FastCGI under IIS7 for a bunch of word press blogs. I came to the end of the install and was setting rights to the wp-content folders so people could upload attachments, but ran into some troubles.  I dunno if this changed because of Service Pack 2, but I found I now have to assign the rights, not to “Network Service” which is the Identity of the app pools, and not to “ISS_IUSRS” group, but to an account simply called “IUSR”.  I’m sure previously i just assigned permission to the network service account?  And surly IUSR would be a member of IIS_IUSR’s by default?  I dunno!  Anyway I had to use procmon to monitor the requests and see which account was actually being used.