so i just setup pptp server using vps and pptp client on mikrotik is success to connect.
but when i try to ping it from server it has not shown the replay. so i just put log at the firewall filter.
here is the result (attachment)
any help i can ping it from vps server ?
nb: i have connect the pptp client using windows 7 and it gives replay

Hey. Try not to NAT pptp clients private addresses with upper NAT rules with accept action. Also check your firewall filter rules before main forwarding rule.