USD Package Deployer unable to connect with Dynamics 365 (Online)
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\.NETFramework\v4.0.30319]
and similarly
[HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Microsoft\.NETFramework\v4.0.30319]
Visit these keys in the registry editor, right click in the right pane, click on 'New >', add dword key as "SchUseStrongCrypto"=dword:00000001
For .net 4.5 and below, strong crypto is disabled by default and only SSL 3.0 and TLS 1.0 will be used for secure connections. By setting these reg-keys TLS 1.0, TLS 1.1 and TLS 1.2 will be used.
Refer:
https://blogs.msdn.microsoft.com/usd/2017/10/20/unified-service-desk-and-tls-1-2-mandate-for-dynamics-365-online/