Error in contact form

On the contact form, when a user fills out the form and submits, all of the info gets emailed to the admin just fine, but the user sees the following error. Also, the "send copy to yourself" function doesn't seem to be working either.

Also, now for some reason, the default home page of the site goes to the contact form

Did you deleted some contacts that were in site by default?

I didn't delete any contacts at all. Can you please tell me how I can restore/fix this?

thanks

Send link to your site so we could test this

dreamdestinations.travel/contact-us