Zwift not launching after Windows 10, 2004 update

Has anyone experienced Zwift not launching after w10 2004 latest feature update ?
Also tried re-installing, still not able to launch. Entries in Log file seems to be ok. Any ideas on how to get get back on Zwift

Are you experiencing the launcher crashing with one of :

  • Zwift encountered the following error: The underlying connection was closed: An unexpected error occurred on a send. Received an unexpected EOF or 0 bytes from the transport stream. If the problem persists please contact Zwift Support.
  • Zwift encountered the following error: The underlying connection was closed: An unexpected error occurred on a receive. The client and server cannot communicate, because they do not possess a common algorithm If the problem persists please contact Zwift Support.

My guess so far is that these are due to Zwift only implementing TLS 1.0 on their servers, and that the windows update now requires TLS 1.2. I’ve found threads asking about this in these two places:


I’m hoping that we can get Zwift to update their servers soon to address this issue, as I have not been able to find a workaround and could not uninstall the windows update (my computer is a work computer so certain updates were mandatory).

AFAIK, Microsoft has announced TLS 1.0 will be disabled no sooner then July 2020 .

Not that there is a reason Zwift wouldn’t move to TLS 1.2 (new worlds not withstanding… )

I finally figured out how to work around this. Enabling TLS 1.0 and 1.1 in Internet Explorer after the recent windows10 updates doesn’t seem to work, but enabling it in regedit key Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.0\Client as in this link does work, at least for me:

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Thanks for the update! :+1:

Thank you James, for feedback
The TLS 1.0 /1.1 reg update didn’t resolve the issue. There is absolutely no error messages, log file is also clean. The Zwift icon disappears after 10sec.

I am receiving the same “unexpected EOF or 0 bytes…” error message. I have all TLS options ‘ticked’ in Explorer. Following the regedit path previously posted is not possible as there is nothing beyond …\protocols in my directory. Can’t get Zwift to run. :sob: