Hello,
I have a problem with using SQLite 3 in the Hurtworld plugin (it's possible that in other types the problem also occurs). Namely: several times reloading the plugin (inserting subsequent versions while creating the plugin) very often crashes the server / connection to the SQLite 3 database ceases to work.
An example of the simplest plugin that causes this problem for me:

using Oxide.Core;
using System;
using Oxide.Core.Database;

namespace Oxide.Plugins
{
    [Info("TestSQLite3", "!Dark!", "1.0.0")]
    [Description("Test Hurtworld SQLite 3")]

    class TestSQLite3 : HurtworldPlugin
    {
        Core.SQLite.Libraries.SQLite sqlLibrary = Interface.Oxide.GetLibrary<Core.SQLite.Libraries.SQLite>();
        Connection sqlConnection;

        private void Loaded()
        {
            Puts("Loading...");
            sqlConnection = sqlLibrary.OpenDb("test.sqlite", this, true);
            sqlLibrary.ExecuteNonQuery(Sql.Builder.Append(
                @"CREATE TABLE IF NOT EXISTS `example_table` (
	                `time`	CHAR ( 50 ),
	                PRIMARY KEY(`time`)
                ) WITHOUT ROWID;"), sqlConnection);

            Insert();
        }

        private void Unload()
        {
            Puts("Unloading...");
            Insert();
            //sqlLibrary.CloseDb(sqlConnection);
        }

        private void Insert()
        {
            string sqlQuery = "INSERT INTO example_table (`time`) VALUES (@0);";
            Sql insertCommand = Oxide.Core.Database.Sql.Builder.Append(sqlQuery, DateTime.UtcNow);

            sqlLibrary.Insert(insertCommand, sqlConnection, rowsAffected =>
            {
                if (rowsAffected > 0)
                {
                    Puts("New record inserted");
                }
            });
        }
    }
}
​

This applies to servers built on Windows and Linux. Error log:

Unity Player [version: Unity 5.3.4f1_fdbb5133b820]

sqlite3.dll caused an Access Violation (0xc0000005)
  in module sqlite3.dll at 0033:017320ca.

Error occurred at 2018-10-28_110210.
E:\server\Hurtworld.exe, run by xxx.
59% memory in use.
16308 MB physical memory [6686 MB free].
18740 MB paging file [5631 MB free].
134217728 MB user address space [134211794 MB free].
Read from location 00000030 caused an access violation.
​

Hurtworld legacy, Oxide 2.0.3893. 
What could be the reason for problems with breaking the connection with SQLite3?

Looks like your database is already open or not writable.

Most often, the console will display a "New record inserted" message before the database crashes. Occurs randomly, but too often.

Merged post

There should be some expectation until the database is available again (when database is busy wait for the final tasks), because currently only the server restart is helping.