I have installed the Arnold HTML 5 theme but the contact form doesn’t appear to be working as expected.
There aren’t any validation errors on the fields though it appears from the code that there should be. The email won’t send if the email isn’t formatted correctly or if fields are left blank but the user isn’t shown any error messages.
Also, when I send an email I get the email success message but the “Sending” message doesn’t disappear so both are shown.
I noticed in web inspector that the file gridstack.min.map was missing (this is the same as in your example site). I found a version of this file online and used this (not sure if this is correct or not).