AGOL hosted feature service just started refusing connections from Windows 2012 R2 server

Question

Hello.

Within the last 36 hours or so from Sept 25, 2025, our AGOL hosted feature services (at least two of them) have started rejecting connections from our Web API. We are using oauth authentication, passing a client id and password to GetToken, then appending the token to subsequent requests to the feature services. The key pieces of the response back from the AGOL hosted service are "The SSL connection could not be established, see inner exception." and the inner exception "Authentication failed because the remote party sent a TLS alert: \u0027HandshakeFailure\u0027."

This is true for multiple servers running Windows 2012 R2. However we have a couple of other servers running Windows 2022 and 2025 where the exact same code is able to connect successfully. I have verified that our Windows 2012 servers are using TLS 1.2. Those same servers are able to get Tokens from the GetToken endpoint but cannot connect to the Hosted Services. For at least the past 6 years prior, the API was happily connecting multiple times per day. This is a recent event.

Any help is appreciated.

Thank you

Timjojo · Answer

Unfortunately not.

We are unable to upgrade the server as well, but were able to move the script to a different server (Windows server 22) to run.

Trippetoe · Answer

@Timjojo   At this point the best Esri tech support is offering is that we just need to update our servers' operating systems. Would it be that simple. While i agree that is clearly the best long term approach, it's not helpful for the short term. Have you heard anything from Esri or figured out anything helpful to resolve this issue?

Timjojo · Answer

We have also ran into this on the 25th around 7:40pm ET on a 2012 server.