error 781: The encryption attempt failed because no valid
certificate was found
When trying to establish a VPN connection to a computer the following
error is encountered:
Connecting to ...
Error 781: The encryption attempt failed because no valid certificate
Possible Causes and Remedies:
- This error can indicate simply that it was not possible to reach
the VPN server across the network.
- Check that the name or IP-address of the VPN server has been
- Try pinging the VPN server, if this fails then consult the notes
on general network connectivity problems.
- This error normally indicates that there is a problem with either
the computer certificate at the VPN server or that there is a problem
with the VPN servers IPSec Policy Agent service.
- This error can also occur due to an intermittent problem (possibly
a windows bug, but at either the client or server end - I don't know).
If everything else looks okay then try it again and it will sometimes
These notes have been tested with Windows 2000.
About the author: Brian Cryer
is a dedicated software developer and webmaster. For his day job he develops websites and desktop applications as well as providing IT services. He moonlights as a technical author and consultant.