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API(v2) Not Working

Occasional Contributor

API(v2) Not Working

I've been using the same code for the last 7 years and for the last week or so it seems like the API to create, send campaigns, lists, contacts, etc is not working at all. Is v2 no longer supporter? I have 2 clients running the same code which has worked for several years and now all I get back on queries to the API is a lot of null values on every call. Can anyone help? I email webservices@constantcontact twice and go reply for the last week. My clients are very upset. I am using the provided C# wrapper.


Re: API(v2) Not Working



It doesn't look like your initial emails about this error came through to us. Our V2 API is still supported, though based on the timing and description of what you are seeing, it may be that your application is trying to connect with an outdated version of TLS.


In August 2018 we announced that our API Key provider (Mashery) would no longer be supporting TLS 1.0/1.1 due to security issues. The official support of TLS 1.0/1.1 stopped in September of 2018, and as of 3/5/19 at about 10am EST our provider began to actively block any secure connection that was not TLS 1.2.


The most details we have are available in our tech blog post about the change:


Because each web server and application is different, I'm not able to provide you with detailed steps on how to ensure everything on your server is up to date. At a high level, you will want to ensure that the following platforms and connections are only using TLS v1.2:

- .NET Framework
- Web services involved in your process
- Web Server your application is hosted on
- Internet Information Services (IIS)
- eCommerce Application


I would recommend reaching out to your server hosting provider for detailed steps on how to check or upgrade your TLS compatibility.


David B.
Tier II API Support Engineer

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