Downloads fail intermittently in Microsoft Edge due to corporate proxy reauthentication and TLS session reuse failure

Hi @Davisd ,

Thanks for reaching out.

From your description, it appears the intermittent download failures happen when Edge tries to resume large HTTPS downloads in a corporate network environment using a proxy. This usually occurs when the proxy server requires reauthentication or rejects TLS session reuse, which interrupts the resumed download.

In simple terms, this happens because Edge tries to continue the secure connection after it was briefly interrupted, but the proxy doesn’t allow that reuse and rejects it - causing the download to fail.

Currently, there isn’t an Edge policy or configuration that disables TLS session reuse or forces a new handshake for each resumed download. This behavior is managed by the underlying Windows network stack and the proxy’s configuration.

You can try the following steps within your organization’s control:

1. Check proxy configuration:
   • Work with your network or proxy administrator to confirm whether TLS session reuse or renegotiation is allowed. Adjusting those settings or extending session timeouts can help.
2. Try alternative methods for large downloads:
   • Use a download manager or command-line tool (such as curl or wget) that can better handle reconnections by starting a new secure session each time.
3. Shorten download sessions:
   • If possible, split large files into smaller parts or download them from a more stable network connection.
4. Keep Edge and Windows updated:
   • Ensure both Microsoft Edge and Windows are fully updated, as newer versions may include general improvements for download reliability.

Since this behavior is caused by how the network proxy handles secure connections, the resolution would need to come from adjustments on the proxy or network configuration side rather than within Edge itself.

If this explanation clarifies the cause and possible next steps, please consider following the instructions in this link: https://learn.microsoft.com/en-us/answers/support/accept-answer - it may help others who encounter the same behavior.

Hope this helps!