To enforce Azure AD Connect to use TLS 1.2 only, run the following Windows PowerShell script in an elevated PowerShell window on each Azure AD Connect server:
$RegPath1 = "HKLM:\SOFTWARE\WOW6432Node\Microsoft\.NETFramework\v4.0.30319" New-ItemProperty -path $RegPath1 ` -name SystemDefaultTlsVersions -value 1 -PropertyType DWORD New-ItemProperty -path $RegPath1 ` -name SchUseStrongCrypto -value 1 -PropertyType DWORD $RegPath2 = "HKLM:\SOFTWARE\Microsoft\.NETFramework\v4.0.30319" New-ItemProperty -path $RegPath2 ` -name SystemDefaultTlsVersions -value 1 -PropertyType DWORD New-ItemProperty -path $RegPath2 ` -name SchUseStrongCrypto -value 1 -PropertyType DWORD
Hope it helps!
Albandrod's Memory 