Troubleshooting/Error: EXCEPTION: Table_bib_main_scan: Field '' not found

I've created a heavily customized reference type, and I think it's causing an error on the marked records page.  Whenever I select a style other than "Style" and click the "Display" button, I receive the error: EXCEPTION: Table_bib_main_scan: Field '' not found.  Any ideas what's causing me to receive this error?

Thanks,
Ben

Please zip all the files

Please zip all the files under "Reftypes" folder and email me the zip. I will try to reproduce it. If you are using version 7, you can unzip a new v7 installation to another folder and see if you can reproduce the problem by changing different conditions. Thanks.