How do I enable TLS 1.2 on ArcGIS Desktop?

Answer

Esri is committed to building and providing strong security for ArcGIS and helping our customers by using the latest security protocols. We strive to implement the highest industry standards, including TLS for data integrity and network security.  

To meet these standards, Esri is making software updates across ArcGIS to support TLS 1.2. As part of improving ArcGIS Online security, Esri is requiring TLS 1.2 connections for ArcGIS Online services. Action is required to ensure continued access to these services. 

The steps to resolve this issue depend on the version of ArcGIS Desktop in use. All currently shipping versions of ArcGIS Desktop require action.

Note:
See the Product Life Cycle pages on the Esri Support site for the support status of each released version of ArcGIS Desktop.

ArcGIS Desktop 10.7:
This release shipped in the first half of 2019 and is configured to use TLS 1.2 – no action is necessary. Esri recommends upgrading to this release when ArcGIS Desktop 10.7 is available.

ArcGIS Desktop 10.6.1 and earlier: 
These releases must be configured to use TLS 1.2. This can be done in two ways:

• OPTION 1 (Recommended) - Installing an ArcGIS Desktop TLS patch. This enables ArcGIS Desktop to run TLS 1.2, but does not affect other applications.
  See: How To: Install the TLS 1.2 patch on ArcGIS Desktop

• OPTION 2 - Setting the operating system to use TLS 1.2. This enables all applications on the system that depend on the Microsoft .NET Framework to use TLS 1.2.
  See: How To: Configure Windows to use TLS 1.2 for ArcGIS Desktop

Note:
Consider your situation when deciding which approach to use–installing the ArcGIS TLS patch or setting the OS environment to enable TLS 1.2. Esri has certified that setting the OS environment to enable TLS 1.2 will not cause problems with ArcGIS; however, setting the OS to use TLS 1.2 may adversely impact other applications. Consult a qualified computer systems professional, if necessary.