Wordpress - Contact Form 7 - Stuck sending contact form

Question

When i try and send my standard contact form in Wordpress using Contact form 7 then it get stuck sending. The form works, i do get the mail to my inbox but visually on the homepage, the form get stuck in "sending mode".

Chrome console say this

Uncaught TypeError: Cannot read property 'dispatchEvent' of undefined
  at Object.wpcf7.triggerEvent (scripts.js?ver=4.9.1:361)
  at ajaxSuccess (scripts.js?ver=4.9.1:279)
  at Object.<anonymous> (scripts.js?ver=4.9.1:344)
  at i (jquery.js?ver=1.12.4:2)
  at Object.fireWith [as resolveWith] (jquery.js?ver=1.12.4:2)
  at y (jquery.js?ver=1.12.4:4)
  at XMLHttpRequest.c (jquery.js?ver=1.12.4:4)

And firefox console says:

TypeError: $target.get(...) is undefined[Läs mer]  scripts.js:361:3
  wpcf7.triggerEvent http://***.se/wp-content/plugins/contact-form-7/includes/js/scripts.js:361:3
  wpcf7.submit/ajaxSuccess http://***.se/wp-content/plugins/contact-form-7/includes/js/scripts.js:279:6
  wpcf7.submit/< http://***.se/wp-content/plugins/contact-form-7/includes/js/scripts.js:344:4
  n.Callbacks/i http://***.se/wp-includes/js/jquery/jquery.js:2:27444
  n.Callbacks/j.fireWith http://***.se/wp-includes/js/jquery/jquery.js:2:28213
  y http://***.se/wp-includes/js/jquery/jquery.js:4:22719.send/c

Do you have good solution to my problem?

Answer 1

In my case the error was caused because i had a file upload field in my form to upload an attachment, and the file was exceeding the post_max_size and upload_max_filesize (php/apache settings). When i changed these two, the problem was gone.