Switch the supported TLS version in .NET 4.0+ on all deployed Cloud Access Manager STS servers to v1.2 in the registry (only the 64 bit entry needs to be modified).
Set or create the key SchUseStrongCrypto DWORD with value 1 at:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\.NETFramework\v4.0.30319
You can also use power shell (as Administrator):
Set-ItemProperty -Path HKLM:\SOFTWARE\Microsoft\.NETFramework\v4.0.30319 -Name SchUseStrongCrypto -Value 1
Use -Value 1 to set all installed versions of .NET 4.0+ to use TLSv1.2 and use -Value 0 to reverse the change.
This change may require a restart of the server to take effect.