NetExtender will not connect and getting security error for Windows 10
03/26/2020 27 14663
Due to the security updates from Microsoft on the Windows 10 platform for SSL traffic. Self-Assigned Certificates are not trusted and can cause connectivity issues from applications using SSL as a form of connecting such as SSLVPN / NetExtender. Typical issues are seen when connecting with NetExtender and getting disconnected right away and a warning error after the disconnect.
Export the SonicWalls Self-Signed HTTPS Management Certificate from Browsers
Select F12 on the keyboard after login to the SonicWall, select on the Security and View certificate button. The certificate will then open to the General tab.
Right click on the Lock and select on the arrow then More Information as shown below.
Select on the View Certificate button then Details tab click Export and save to a location on the Windows 10 computer making sure to name with a friendly name to make it easy to locate.
(Both Browsers) Select on the Details tab of the Certificate. Click Copy to File button and use the Wizard as showing below to Export the certificate from the browser.
Select the radio button for Base-64 encoded X.509 (.CER) then click Next. Browser to a location on the Windows 10 computer to save the Certificate. Making sure to name with a friendly name to make it easy to locate for later.
Once the Certificate if saved the next step is to make it Trusted on the Windows 10 computer.
Adding the SonicWalls Self Signed HTTPS Management Certificate to the Windows 10 computers to make it trusted.
Open MMC and click File then Add or Remove Snap-ins.
Select on Certificates and then Add.
Select radio button for Computer account.
Confirm Local Computer then select on Finish, click OK.
Expand and select on Trusted Root Certification Authority then Certificate | all Tasks | Import.
The Welcome to the Certificate Import Wizard will pop-up click Next.
Click Browse button and navigate to the Certificate saved earlier.
Leave the default for placing the certificate and click Next.
Click Finish to complete the import of the Self-Signed Certificate from the SonicWall management.
You should not see a warning again for the Certificate not being trusted from this Windows 10 computer or Security Errors and disconnections in NetExtender for these errors. This type of Security Error is typically caused when using a HTTPS URL that does not have a Public Certificate assigned to it.