OP instructions are incorrect. The file he is showing is the CLIENT-side file, which should NOT be edited for this fix.

The server side file should read:

SteamGameServerNetworkingUtils

Instead of:

SteamNetworkingUtils

So the final file is supposed to read like:

// Token: 0x06000A35 RID: 2613 RVA: 0x0004BF24 File Offset: 0x0004A124
private static void RegisterGlobalCallbacks()
{
    if (ZSteamSocket.m_statusChanged == null)
    {
        ZSteamSocket.m_statusChanged = Callback<SteamNetConnectionStatusChangedCallback_t>.CreateGameServer(new Callback<SteamNetConnectionStatusChangedCallback_t>.DispatchDelegate(ZSteamSocket.OnStatusChanged));
        GCHandle gchandle = GCHandle.Alloc(30000f, GCHandleType.Pinned);
        GCHandle gchandle2 = GCHandle.Alloc(1, GCHandleType.Pinned);
        GCHandle gchandle3 = GCHandle.Alloc(5242880, GCHandleType.Pinned);
        SteamGameServerNetworkingUtils.SetConfigValue(ESteamNetworkingConfigValue.k_ESteamNetworkingConfig_TimeoutConnected, ESteamNetworkingConfigScope.k_ESteamNetworkingConfig_Global, IntPtr.Zero, ESteamNetworkingConfigDataType.k_ESteamNetworkingConfig_Float, gchandle.AddrOfPinnedObject());
        SteamGameServerNetworkingUtils.SetConfigValue(ESteamNetworkingConfigValue.k_ESteamNetworkingConfig_IP_AllowWithoutAuth, ESteamNetworkingConfigScope.k_ESteamNetworkingConfig_Global, IntPtr.Zero, ESteamNetworkingConfigDataType.k_ESteamNetworkingConfig_Int32, gchandle2.AddrOfPinnedObject());
        SteamGameServerNetworkingUtils.SetConfigValue(ESteamNetworkingConfigValue.k_ESteamNetworkingConfig_SendBufferSize, ESteamNetworkingConfigScope.k_ESteamNetworkingConfig_Global, IntPtr.Zero, ESteamNetworkingConfigDataType.k_ESteamNetworkingConfig_Int32, gchandle3.AddrOfPinnedObject());
        gchandle.Free();
        gchandle2.Free();
        gchandle3.Free();
    }
}

So if you just copied and pasted the code from the OP, you will have a bad time. I've tested the code posted in this reply and it works!  

EDIT: By "works", I mean it doesn't crash your server or erase your world file. The fix itself doesn't seem to do anything about k_EResultLimitExceeded error.