'Sending' animation does not complete – any tips?

Well, you could have a server-side problem like this guy:
https://www.ads-software.com/support/topic/icon-spinning-after-submit-disabled-plugins-and-switched-themes-not-working?replies=4

Or, you could have a Javascript conflict like this guy:
https://www.ads-software.com/support/topic/no-confirmation-message-when-using-on_sent_ok?replies=15

Quickest method to prove this is a conflict with someone else’s code is to (temporarily) disable every other plugin and revert to the default theme and try the contact form again.

Thanks, I did the plugin route and it turns out the CF7 campaign monitor extension is the plugin that breaks it. Question now is, how do I fix it?

I’m not doing anything fancy with my forms so no idea why these to don’t play nice together, but I can’t be alone

You’ll have to follow up with the author of CF7 campaign monitor.

Hello friends ContactForm7
I did the upgrade to 4.2.1, and the ContactForm7 crashed. See the return message I get.

Could not send your message.
Please try again later or contact
the administrator by another method.

What should I do?

@reinaldo Camacho – As per the Forum Welcome, please post your own topic.

Posting in an existing topic and taking over the original posters question is generally considered inappropriate.

Added to which, your problem – despite any similarity in symptoms – is likely to be completely different