Pinterest has your Hosting IP in the list of potentially suspicious networks and blocked it. This means your hosting provider was recently used to abuse Pinterest.
This usually happens when:
  – You use some “cloud cdn” providers like CloudFlare or Incapsula.
  – You are on shared hosting and one of your neighbours was/is abusing Pinterest.
  – You are hosted on some “activity friendly” providers like Amazon AWS, LeaseWeb, OVH, RedStation, ServerCentral, SoftLayer, etc.

1. Try to contact Pinterest and ask them to unblock your IP.

  All you need to do is to fill one form on

   1. Choose “Getting into my account”, then “Get out of safe mode”, then click “I still need help”

   2. Fill your issue info with your website IP and say “I am not running any bots, please allow me to use my account”.

2. If you are using CloudFlare or one of the permanently blocked providers you can use proxy. (You can configure it in the “Advance tab”)