PPTP not working on linux lite

[Stan Hui]

I have a VPN running on windows 2016 server with PPTP. I can connect it by any windows platform and android phones.
However it can not be connected in LINUX lite.
I search here and do the following settings

Click the NetworkManager Icon in System Tray
VPN Connection -> Edit VPN -> <VPN> -> Add +
Choose <Point-to-Point Tunneling Protocol (PPTP)> ->
Fill the gateway as the VPN server IP.
Username field is fine,password field is read only.
select save password for everyone, then the field is write-able.

click Advanced
In Authentication section, CANCEL <PAP>, <CHAP>, and <EAP>, KEEP ONLY <MSCHAP> and <MSCHAPv2> SELECTED.
In Security and Compression section, SELECT <Use Point-to-Point encryption (MPPE)>, and choose Security to be <All Available (Default)>
OK -> Accept -> Close
Reboot or Re-start networking
Now click the NetworkManager Icon



none message shown up but just says can not connect to server.

what else should I do to make it work?

Thanks

[Valtam]

Take a look at this first - https://askubuntu.com/questions/572497/c...ernel-3-18 for possible Firewall issue.

Also - https://askubuntu.com/questions/1030866/...g-on-18-04