Quote Originally Posted by bmalex56 View Post
Any suggestions on what could be the problem??
I've not been able to reproduce either, but only two things really come to mind.

File or folder permissions is the 1st thing I think of when I see 500 Server errors (either too restrictive or not restrictive enough).
However, I don't think that this would be the case here due to the fact that it is (apparently) only with order totals of zero. This may be a red herring though, so check the permissions anyway.

My other idea has already been covered by Ajeh......

"Are you using any kind of SEO/rewrites? If so, turn them off and see if that is the issue ..."

If neither of these ideas are applicable you will probably need to contact your host for help. Their log files will provide more specific information as to the exact cause. The '500 Server Error' is a generic error response designed to not leak information that could be used to compromise the server.

Cheers
RodG