Mailchimp for Woocommerce has not added the webhook to Mailchimp

I’ve been getting this message but have now tracked down the cause in my case so I’m posting it here in case it helps anybody else.

I use Cloudflare and have a web application firewall rule set up there to issue a managed challenge to incoming traffic if certain criteria (origin country, permitted IPs etc.) are not met. All I needed to do was add the following test to avoid doing that if the request has the MailChimp webhook validator user agent and all was well.

http.user_agent ne “MailChimp.com WebHook Validator”

Note that I’m testing for the user agent NOT being “MailChimp.com WebHook Validator”. If you want to test that it IS that value then use:
http.user_agent eq “MailChimp.com WebHook Validator”

Alasdair