How do I prevent or solve 'database is locked' error in C# sqlite?

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C#

database

SQLite

Hello, everyone.
I have some problems in c# SQLite data update and creating.
I'm using SQLite as a database in my c# windows form application.
By the way, sometimes I've got a "database is locked" error in SQLite, when I try to insert or update data.
While searching the way on google, I got know that it will be able to happen because multi-threads is working or the database is in processing.
But I can't find what thread or process hurt this database updating correctly.
I want to prevent the error and finally solve this problem asa.
Thanks for your time.

What I have tried:

static SQLiteConnection CreateConnection(string dbName)
{

    SQLiteConnection sqlite_conn;
    // Create a new database connection:
    sqlite_conn = new SQLiteConnection("Data Source=" + dbName + ".db; PRAGMA journal_mode = WAL; Version = 3; New = True; Compress = True; Connection Timeout=0 ");
    // Open the connection:
    try
    {
        sqlite_conn.Open();
    }
    catch (Exception ex)
    {
        Console.WriteLine(ex);
    }
    return sqlite_conn;
}

sqlite_conn = CreateConnection(constants.dbName);
InsertLog(sqlite_conn, 2, "xxx", "yyyyy");

public void InsertLog(SQLiteConnection conn, int logType, string logTitle, string logContent, string logContent_2 = "")
{
    if (conn.State == ConnectionState.Closed)
    {
        conn.Open();
    }
    try
    {
        DateTime logDate = DateTime.Now;
        SQLiteCommand sqlite_cmd;
        string Createsql = "INSERT INTO " + constants.tbNames[14] + " (logType, logTitle, logContent, logContent_2, logDate) VALUES (@logType, @logTitle, @logContent, @logContent_2, @logDate)";
        sqlite_cmd = conn.CreateCommand();
        //sqlite_cmd.CommandTimeout = 0;
        sqlite_cmd.CommandText = Createsql;
        sqlite_cmd.Parameters.AddWithValue("@logType", logType);
        sqlite_cmd.Parameters.AddWithValue("@logTitle", logTitle);
        sqlite_cmd.Parameters.AddWithValue("@logContent", logContent);
        sqlite_cmd.Parameters.AddWithValue("@logContent_2", logContent_2);
        sqlite_cmd.Parameters.AddWithValue("@logDate", logDate);

        sqlite_cmd.ExecuteNonQuery();

    }
    catch (Exception e)
    {
        conn.Close();
        //Console.WriteLine("db_error==" + e);
        return;
    }
    conn.Close();
    return;
}