И только в крайнем случае рассматривал эти Poverline
[Unit]
Description=SSTP VPN server
After=network.target
[Service]
Type=simple
ExecStart=/usr/local/bin/sstpd -f /etc/sstpd.ini
Restart=on-failure
RestartSec=30
[Install]
WantedBy=multi-user.target
2025-01-27 16:00:00,915 INFO: SSTP control packet (CALL_CONNECT_REQUEST) received.
Jan 27 16:00:00 51285.ip-ptr.tech sstpd[8473]: 2025-01-27 16:00:00,917 INFO: Registered address 172.16.117.5
Jan 27 16:00:00 51285.ip-ptr.tech sstpd[8473]: 2025-01-27 16:00:00,923 WARNING: Received errors from pppd.
Jan 27 16:00:00 51285.ip-ptr.tech sstpd[8473]: 2025-01-27 16:00:00,924 WARNING: b'/usr/sbin/pppd: The remote system is required to authenticate itself\n'
Jan 27 16:00:00 51285.ip-ptr.tech pppd[8485]: The remote system is required to authenticate itself
Jan 27 16:00:00 51285.ip-ptr.tech sstpd[8473]: 2025-01-27 16:00:00,925 WARNING: Received errors from pppd.
Jan 27 16:00:00 51285.ip-ptr.tech sstpd[8473]: 2025-01-27 16:00:00,925 WARNING: b"/usr/sbin/pppd: but I couldn't find any suitable secret (password) for it to use to do so.\n"
Jan 27 16:00:00 51285.ip-ptr.tech pppd[8485]: but I couldn't find any suitable secret (password) for it to use to do so.
Jan 27 16:00:00 51285.ip-ptr.tech sstpd[8473]: 2025-01-27 16:00:00,926 WARNING: Received errors from pppd.
Jan 27 16:00:00 51285.ip-ptr.tech sstpd[8473]: 2025-01-27 16:00:00,926 WARNING: b'/usr/sbin/pppd: (None of the available passwords would let it use an IP address.)\n'
Jan 27 16:00:00 51285.ip-ptr.tech pppd[8485]: (None of the available passwords would let it use an IP address.)
Jan 27 16:00:00 51285.ip-ptr.tech sstpd[8473]: 2025-01-27 16:00:00,928 INFO: pppd exited with code 1.
Jan 27 16:00:01 51285.ip-ptr.tech sstpd[8473]: 2025-01-27 16:00:01,289 INFO: Connection finished.
Jan 27 16:00:01 51285.ip-ptr.tech sstpd[8473]: 2025-01-27 16:00:01,290 WARNING: PPP process is gone already
Jan 27 16:00:01 51285.ip-ptr.tech sstpd[8473]: 2025-01-27 16:00:01,290 INFO: Unregistered address 172.16.117.5
root@51285:/home/stealch# systemctl status sstpd.service
* sstpd.service - SSTP VPN server
Loaded: loaded (/etc/systemd/system/sstpd.service; disabled; vendor preset: enabled)
Active: active (running) since Mon 2025-01-27 13:53:37 EET; 5min ago
Main PID: 1591 (sstpd)
CGroup: /system.slice/sstpd.service
`-1591 /usr/bin/python3 /usr/local/bin/sstpd -f /etc/sstpd.ini
Jan 27 13:53:37 51285.ip-ptr.tech systemd[1]: sstpd.service: Service hold-off time over, scheduling restart.
Jan 27 13:53:37 51285.ip-ptr.tech systemd[1]: Stopped SSTP VPN server.
Jan 27 13:53:37 51285.ip-ptr.tech systemd[1]: Started SSTP VPN server.
Jan 27 13:53:37 51285.ip-ptr.tech sstpd[1591]: 2025-01-27 13:53:37,441 INFO: Cert SHA-1: 2e148f316d4e20249aa24e8154b3f730336836ee
Jan 27 13:53:37 51285.ip-ptr.tech sstpd[1591]: 2025-01-27 13:53:37,442 INFO: Cert SHA-256: f996d570fbd82ebb7b6e4260384c9e24ae32c43285f39990e7b48b07d3719175
Jan 27 13:53:37 51285.ip-ptr.tech sstpd[1591]: 2025-01-27 13:53:37,443 INFO: Running without uvloop
Jan 27 13:53:37 51285.ip-ptr.tech pppd[1593]: /usr/lib/pppd/2.4.7/sstp-pppd-plugin.so: cannot open shared object file: No such file or directory
Jan 27 13:53:37 51285.ip-ptr.tech pppd[1593]: Couldn't load plugin sstp-pppd-plugin.so
Jan 27 13:53:37 51285.ip-ptr.tech sstpd[1591]: 2025-01-27 13:53:37,461 INFO: Listening on 0.0.0.0:443...
root@51285:/home/stealch# journalctl -u sstpd.service
-- Logs begin at Mon 2025-01-27 13:43:55 EET, end at Mon 2025-01-27 13:48:57 EET. --
Jan 27 13:48:33 51285.ip-ptr.tech systemd[1]: Started SSTP VPN server.
Jan 27 13:48:33 51285.ip-ptr.tech sstpd[1284]: 2025-01-27 13:48:33,893 CRITICAL: [Errno 2] No such file or directory
Jan 27 13:48:33 51285.ip-ptr.tech sstpd[1284]: 2025-01-27 13:48:33,894 CRITICAL: Cannot read certificate.
Jan 27 13:48:33 51285.ip-ptr.tech systemd[1]: sstpd.service: Main process exited, code=exited, status=2/INVALIDARGUMENT
Jan 27 13:48:33 51285.ip-ptr.tech systemd[1]: sstpd.service: Unit entered failed state.
Jan 27 13:48:33 51285.ip-ptr.tech systemd[1]: sstpd.service: Failed with result 'exit-code'.
Зачем вы применили атрибут [STAThread] к метод Install?
просто указать static async Task Main()