eForm + IIS7 - no longer working

We launched a site in 2010 in a Windows environment. This is the client's hosting, not ours as we use a LAMP server. We took the steps outlined for optimal MODx experience on IIS. Since then we've had little to no issues with the forms or the site itself.

As of a few weeks ago, 2 of the forms using eForm (1 is not using eForm), now give a 500 Internal Server Error when you submit the form.

I've edited, rearranged, crossed my fingers and toes, prayed but nothing I change about the eform call fixes the issue.

This leads me to think it is the server itself - given that it is a 500 Internal Server Error.

My question to those reading would be how to approach this issue. The client claims no updates/changes have been made to the server. What else should I be looking into if it's not the server itself?

Some additional info:

Windows IIS7
PHP v 5.2.6
MODx v 1.0.4
eForm v 1.4.4.6

Hi,

Are you using the site with friendly URLs? what happens when you disable this and try out the eForm?

Also on the server depending on your PHP set-up you should have a php-error log some where or you might see some errors in the windows event logs under application which could give more of a pointer to what the issue is.

Thanks