I use go-openvpn as openvpn client to connect server.
I use the example code for desk to build the ‘test.exe’, when I run it with admin privilege, it quickly pop-up and close cmd window 3 times. It closes too quick to see what’s content in the window.

I recorded a video of the phenomenon

How to stop pop-up window?

Here is my example code, I only add a timer to close the session. go build -ldflags "-w -s -H windowsgui" -o test.exe

package main

import (
    "fmt"
    "io/ioutil"
    "os"
    "strings"
    "time"

    "github.com/mysteriumnetwork/go-openvpn/openvpn3"
)

type callbacks interface {
    openvpn3.Logger
    openvpn3.EventConsumer
    openvpn3.StatsConsumer
}

type loggingCallbacks struct {
}

func (lc *loggingCallbacks) Log(text string) {
    lines := strings.Split(text, "n")
    for _, line := range lines {
        fmt.Println("Openvpn log >>", line)
    }
}

func (lc *loggingCallbacks) OnEvent(event openvpn3.Event) {
    fmt.Printf("Openvpn event >> %+vn", event)
}

func (lc *loggingCallbacks) OnStats(stats openvpn3.Statistics) {
    fmt.Printf("Openvpn stats >> %+vn", stats)
}

var _ callbacks = &loggingCallbacks{}

// StdoutLogger represents the stdout logger callback
type StdoutLogger func(text string)

// Log logs the given string to stdout logger
func (lc StdoutLogger) Log(text string) {
    lc(text)
}

func main() {

    var logger StdoutLogger = func(text string) {
        lines := strings.Split(text, "n")
        for _, line := range lines {
            fmt.Println("Library check >>", line)
        }
    }

    openvpn3.SelfCheck(logger)

    bytes, err := ioutil.ReadFile("./client1.ovpn")
    if err != nil {
        fmt.Println(err.Error())
        os.Exit(1)
    }
    config := openvpn3.NewConfig(string(bytes))

    session := openvpn3.NewSession(config, openvpn3.UserCredentials{}, &loggingCallbacks{})
    session.Start()

    time.Sleep(20 * time.Second)
    session.Stop()
    os.Exit(0)
}

Here is my client ovpn config file

client
dev tunkj
proto tcp
nobind
remote address port
fast-io
persist-key
verb 3
script-security 3
connect-retry 3 6
connect-timeout 6
ping 5
ping-restart 20
up-delay
<auth-user-pass>
username
password
</auth-user-pass>
auth-nocache
topology subnet
<ca>
-----BEGIN CERTIFICATE-----
...
-----END CERTIFICATE-----
</ca>

I use this command go build -ldflags "-w -s -H windowsgui" -o test.exe to disable cmd window.

I expecting to stop pop-up window when starting connection. Or the way to record the content in cmd window, so i can locate what cause this.