Contact Form 7 stuck with spinning resfresh arrows after hitting Submit

Same issue —?upgraded from 4.9.10 to 5.1.1, and the spinner never stops.

Downgraded back to Contact Form 7 version 4.5.
Seems to work as it worked earlier.

The spinning arrow is a common sign of a JavaScript conflict. The problem is likely due to a conflict with your WP theme or one of the other plugins you are using.

Downgrading to an old version of CF7 doesn’t deal with the real issue.

Switch temporarily (nothing will be lost when you switch back) to a WP default theme & disable all plugins other than Contact Form 7 to see if the problem goes away.

If it does you can switch back to your theme & re-activate each plugin one by one to see when the problem occurs.

That’s all well and good Neil, but for me at least, changing to a WP default theme and disabling all plugins except Contact Form 7 changes nothing – the spinning arrow still sits there indefinitely and the form doens’t check for required fields.

So downgrading to an old version is the only option, since the problem is clearly with the newer versions of the plugin.

Switching temporarily is a technique commonly used in WordPress to find what is actually causing a particular problem.

Health Check is a good way to check this on a live site. It’s planned to be made part of WordPress Core in coming releases.

Rather than rolling back an update?—?we noticed that forms that only had an email address available (didn’t ask for name) but were passing the [your-name] tag to the Mailchimp plugin were the only forms that were erroring (500, spinning forever).

For those forms, we changed the mailchimp settings to pass a temporary non-empty string to Mailchimp. This caused the forms to submit successfully.

I believe the error is caused by a change in what fields are required and how empty fields are handled (by the plugin or by Mailchimp). This is a new change though.