It’s probably that the configuration file is directly copied and pasted, resulting in invisible strange strings. If you honestly modify the configuration file without leaving strange spaces, you will not report this error. The configuration file is parsed by UCI. The configuration file of pptpd is in the/etc/config/pptpd file. The content is as follows,

config service 'pptpd'
option enabled '1'
option localip '192.168.0.1'
option remoteip '192.168.0.2-30'
option nat '1'
option internet '1'
#list dns '192.168.1.1'
#list dns '10.10.0.21'
option mppe '1'


config login
option enabled '1'
option username 'user2'
option password 'dfsaf'
option ipaddress '192.168.0.2'

/etc/init.d/pptpd restart
/etc/init.d/pptpd start
Both can open pptpd server now
netstat -antp
Check if port 1723 is open, if it is open, it is running.
For sh out of range, see:

https://forum.openwrt.org/t/default-config-file-for-pptpd-lacks-logwtmp-option/4795

######/etc/firewall.user###########

iptables -A forwarding_rule -i ppp+ -j ACCEPT ## luci-app-pptpd
iptables -A forwarding_rule -o ppp+ -j ACCEPT ## luci-app-pptpd
iptables -A output_rule -o ppp+ -j ACCEPT ## luci-app-pptpd
iptables -A input_wan_rule -p tcp --dport 1723 -j ACCEPT ## luci-app-pptpd
iptables -A input_wan_rule -p tcp --dport 47 -j ACCEPT ## luci-app-pptpd
iptables -A input_wan_rule -p gre -j ACCEPT ## luci-app-pptpd
iptables -A input_rule -i ppp+ -j ACCEPT ## luci-app-pptpd