vSphere Client fails to start with the error: The requested security protocol is not supported

Products

• VMware vCenter Server
• VMware vSphere ESXi

Issue/Introduction

Symptoms:

• vSphere Client fails to start.
• You see the error:
  
  The requested security protocol is not supported
  

Environment

VMware vSphere ESXi 6.0
VMware vCenter Server 6.0.x

Resolution

To resolve this issue, install the .NET Framework update to enable the use of TLS v1.2.

 

To download the .Net Framework update:

• For .NET Framework 2.0 SP2 on Windows Vista SP2 and Server 2008 SP2, see the Microsoft Knowledge Base 3154517.
• For .NET Framework 3.5.1 on Windows 7 SP1 and Server 2008 R2 SP1, see the Microsoft Knowledge Base 3154518.
• For .NET Framework 3.5 on Windows Server 2012, see the Microsoft Knowledge Base 3154519.
• For .NET Framework 3.5 on Windows 8.1 and Windows Server 2012 R2, see the Microsoft Knowledge Base 3154520.