All MODX processing is done in its main index.php file. All other scripts (including the FormIt handling scripts) are included into that index.php file as required during processing.
For handling attachments with FormIt, see http://codingpad.maryspad.com/2011/03/09/modx-revolution-adding-an-attachment-field-to-a-formit-form/
I too have just encountered this problem with my site hosted on GoDaddy. Using Formit 2.2.11pl and MODX 2.5.1pl
The last time we received a .docx file was July, so this could have been broken for some time. It's only since I upgraded to 2.5.1 and been testing did I find it.
Apache error logs report:
fcgid:warn] (9)Bad file descriptor: [client ] mod_fcgid: ap_pass_brigade failed in handle_request_ipc function, referer attachment-test.html
Trying to send a .docx attachment resets the server. I think it's probably a GoDaddy configuration issue, but they're always going to blame the plugin/extra. My most recent support call they insisted that I update my WordPress plugin. I gave up telling them it was MODX formit and up to date! So I'm desperately trying to build a solid case to go back to them.
I've checked the enctype and it used to work fine previously so I don't know why it wouldn't now and all other file types are fine. doc/pdf/txt etc.
Any help would be greatly appreciated.
I've seen lots of complaints here about GoDaddy.
My guess would be an issue with mod_security
It would not be surprising at all to find mod_security reacting to a .docx attachment, though resetting the server sounds a little extreme.