Unknown yellow box message on error

CF7 has been working very well on this site with six different forms, but adding a new form with an attachment upload isn’t working. After submitting, I get a yellow border message box with no message, so I have no idea what is wrong, I have nothing to work with. The CSS for the message box has selectors of .wpcf7 form.invalid .wpcf7-response-output so that obviously means a problem message, but the there is no text. Only a yellow border box.

I know I set up the upload feature correctly and it’s selecting a very small file. I have the tag in the mail area ready to go.

The link here is to a non-public test page.

Here is my tag structure:

<label> Your name
    [text* your-name] </label>

<label> Your email
    [email* your-email] </label>

<label> Your phone
    [tel* tel-47] </label>

<label> Your message (optional)
    [textarea your-message] </label>

<label> Your resume (pdf, jpg, doc files only – limit 2mb)
    [file* your-file filetypes:pdf|txt|doc limit:2mb] </label>

[anr_nocaptcha g-recaptcha-response]

[submit "Submit"]

Here is my mail structure:

From: [your-name] <[your-email]>
Subject: Employment Application

Name:
[your-name]

Email:
[your-email]

Phone:
[tel-47]

Message Body:
[your-message]

and [your-file] is located in the File Attachments field down below.

The page I need help with: [log in to see the link]