What is the cause of the SoftEther VPN server not working?

Which protocol is implemented in SoftEther?

Windows, Linux, FreeBSD or even DOS. You can install rpmlint Perl program to check the rpmbuild scripts to make sure there are no issues before building the rpm package from them. As far as I know, SoftEther is a console based network configuration tool. And it's only networking driver which is PPPoE is softether and seems not to be included in standard rpm package catalog (as documented in its ftp site). Zensetting ready only, you have 3 choices now, either to install softether module from packages, or separately download the source code, and build softether from source (there is also tar ball available).
Update 2020-01-16: Revert above answer.

What is the cause of the SoftEther VPN server not working?

It's more than likely a wrong installation or virtual machine.

I have just installed latest version of SoftEther VPN Server, this version is 2.0, downloaded the zip file from After installation I checked all the settings for server, and configured CA certificates, routes as well as.crt files and allowed all exceptions. Once finished with that I restarted the VM and now it keeps saying Connection failed - You cant connect to X gateway. Here are the my logs is what I am having. Server 0.200006

Logging #2 2012-08-09 10:27:17,Server Output(some information removed)2012-08-09 10:27:17,Device ManagerOutputSide 1Setting the referenced registry value (REG.hiveSOFTETHERSoftEtherVPN9NVF 1AM810)) was successful.

Side 2Calling Level 3 Negotiation Setup for Windows 7 something like NT service STARTUP. Connecting to shared session@dns.softether VPN.

What I would suggest is to use an external MAC address / IP address if possible in Active Directory to be able to connect.