We have been dealing with a very frustrating VPN issue that was only occurring with our newer Dell Laptops, below is the fix I found and wanted to share with the community at large.
Newer Dell laptops have a piece of software called "SmartByte" I found this piece of software was blocking our access to our VPN. Once I disabled this software I was able to successfully log in to the VPN. To fix the issue launch the "SmartByte" software from the Start menu. There is an on off toggle, turn off "SmartByte" and you are able to connect. You are able to uninstall the software and it does no harm to the system.
I am attaching a screen shot of the SmartByte screen as well.
This software is installed by default on all Dell laptop systems since about June of 2017. I have not tested this with any desktop models.
@PhilipDAth because someone at Dell is friends with someone at the company that develops that software. Just like everything in this world its about knowing people in the right places.
I spend eaily 20+ hours online and offline with Meraki support regarding this issue with no resolution. VPN just dont connect with those new Dell Laptop unless i format it and reinstall a clean OS. SmartByte !! Its you all along !!
On newer new Dell PC's (XPS 13 here) it seems SmartByte has been replaced with "Killer Control Center." Toggling off the "Advanced Stream Detect" switch under Settings tab in Killer Control Center fixes the 809 error when connecting to the VPN.