I want to set up PPTP (VPN) server on my server (Router OS for X86 ) but after configure all setting can not connect to this server and see error about GRE protocol
my setting is
/ip firewall filter
add action=accept chain=input disabled=no
add action=accept chain=input disabled=no protocol=tcp src-port=1723
add action=accept chain=input disabled=no protocol=udp src-port=1723
add action=accept chain=input connection-state=established disabled=no
add action=accept chain=input disabled=no protocol=gre

/ppp profile
set default change-tcp-mss=yes name=default only-one=default use-compression=\
default use-encryption=default use-ipv6=yes use-mpls=default \
use-vj-compression=default
add change-tcp-mss=default dns-server=***** local-address=\
VPN-OVPN name=VPN-SHIRAZU-PROFILE only-one=default use-compression=\
default use-encryption=yes use-ipv6=yes use-mpls=default \
use-vj-compression=default
set default-encryption change-tcp-mss=yes name=default-encryption only-one=\
default use-compression=default use-encryption=yes use-ipv6=yes use-mpls=\
default use-vj-compression=default
/ppp aaa
set accounting=yes interim-update=1m use-radius=yes
/ppp secret
add caller-id="" disabled=no limit-bytes-in=0 limit-bytes-out=0 name=admin \
password="7700" profile=VPN routes="" service=any

I read the documentation and see
this paragraph "Note that it is not possible to add new services, only existing service modifications are allowed. "

can anyone help me about this problem

Hello, do you have any radius server? because:

/ppp aaa
set accounting=yes interim-update=1m use-radius=yes

this mean yes, and if you haven't got you must be disabled "use radius=yes" and use the "secrets" for authenticated.
if you have a radius server then the user/pass is consulted in him not in your mikrotik/section "secrets"

the chain in firewall must be dst-port=1723 because the pptp client will look for this port in mikrotik router.

best regards,

i use free-radius as radius accounting server and no problem with hotspot RAS
i correct all of setting and set on local accounting (secret part) but can not connect
but i see on my client can not connect to vpn server with error 806 about GRE protocol
for troubleshooting this problem i connect to server with cross-over cable "Ethernet to Ethernet"to my laptop but still have same problem

can you guide me about better configuration

Ok, export your firewall conf.

I have the same problem! What is the fix? for this error?