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How To: Configure Windows to use TLS 1.2 for applications that use the .NET 3.5.1 Framework


As part of improving ArcGIS Online security, Esri requires TLS 1.2 connections for ArcGIS Online services. Action is necessary to ensure access to these services.

The steps provided describe how to set the Windows operating system to use TLS 1.2. This enables all applications on the system that depend on the Microsoft .NET Framework 3.5.1 to use TLS 1.2. This is an operating system-level change and should only be done once. If you have already used these instructions and created the Windows Registry keys that enable TLS 1.2 on Windows for another Esri product, it is not necessary to repeat these steps.

This is an optional method for configuring ArcGIS applications to use TLS 1.2 when a product upgrade to explicitly support TLS 1.2 is not available or cannot be applied. The recommended solution is to upgrade to a product version that supports TLS 1.2. For information, see the Esri TLS Support page. Consider your situation carefully when deciding which approach to use – setting the OS environment to enable TLS 1.2 will not cause ArcGIS any problems, however, this may impact other .NET applications by changing their default TLS behavior.


If the system is using .NET Version 3.5.1, and it is not feasible to install .NET4, use the following steps to enable TLS 1.2:

  1. Install Microsoft updates to enable TLS 1.2. The following updates are available:
  2. Download the following zip file: TLS_NET35.zip.
  3. Extract the file TLS_NET35.reg, and open the file to create the appropriate Windows Registry keys.
  4. Test your TLS 1.2 Connections to ArcGIS Online.

Related Information

Last Published: 11/14/2018

Article ID: 000019426