NET Framework to enable TLS 1.2+, see Configure for strong cryptography. Resolutionįor more information about how to configure. The Business Data Connectivity Metadata Store is currently unavailable. : An existing connection was forcibly closed by the remote host. System.IO.IOException: Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host. : The underlying connection was closed: An unexpected error occurred on a send. > : The remote server returned an error: (401) Unauthorized.Īt () You experience one or more of the following errors when you access SharePoint: If you haven't taken steps to prepare for this change, your connectivity to Microsoft 365 might be affected.NET Framework not configured for TLS 1.2 Symptom Support for TLS 1.2+ will continue to be added to all Microsoft 365 environments for the next several months.

As previously communicated in the Microsoft 365 Admin Center (for example, communication MC240160 in February 2021), we're moving all online services to Transport Layer Security (TLS) 1.2+.

.net app to test tls 1.2