Can't connect with network-manager-pptp

I need to establish a vpn with pptp protocol from my ubuntu to a windows machine.
I installed the network-manager-pptp paquet and created a vpn. But it failed. See the log in /var/log/messages :
Dec 10 09:52:46 nm-laptop pppd[8876]: Plugin /usr/lib/pppd/2.4.4/nm-pptp-pppd-plugin.so loaded.
Dec 10 09:52:46 nm-laptop pppd[8876]: pppd 2.4.4 started by root, uid 0
Dec 10 09:52:46 nm-laptop pppd[8876]: Using interface ppp0
Dec 10 09:52:46 nm-laptop pppd[8876]: Connect: ppp0 <--> /dev/pts/1
Dec 10 09:52:50 nm-laptop pppd[8876]: EAP: Identity prompt "Name"
Dec 10 09:52:50 nm-laptop pppd[8876]: EAP: Identity prompt "Name"
Dec 10 09:52:50 nm-laptop pppd[8876]: Connection terminated.
Dec 10 09:52:50 nm-laptop pppd[8876]: Exit.

I read somewhere that we should disable EAP authentication to have the MSCHAP v2 one but I don't know how to do.

I also tryied with the terminal command pptpsetup :
sudo pptpsetup --create _tunel_name_ --server _server_name_ --username _username_ --password _pass_ --encrypt --start
But the output give :
Using interface ppp0
Connect: ppp0 <--> /dev/pts/1
EAP: Identity prompt "Name"
EAP authentication succeeded
MPPE required, but MS-CHAP[v2] auth not performed.
Connection terminated.

Someone do know how to establish a VPN with pptp?
Thank you so much.