CryptoExchange.Net/docs/FAQ.md

---
title: FAQ
nav_order: 11
---

## Frequently asked questions

### I occasionally get a NullReferenceException, what's wrong?
You probably don't check the result status of a call and just assume the data is always there. `NullReferenceExecption`s will happen when you have code like this `var symbol = client.GetTickersAync().Result.Data.Symbol` because the `Data` property is null when the call fails. Instead check if the call is successful like this:
```csharp
var tickerResult = await client.GetTickersAync();
if(!tickerResult.Success)
{
  // Handle error
}
else
{
  // Handle result, it is now safe to access the Data property
  var symbol = tickerResult.Data.Symbol;
}
```

### The socket client stops sending updates after a little while
You probably didn't keep a reference to the socket client and it got disposed.
Instead of subscribing like this:
```csharp
private void SomeMethod()
{
  var socketClient = new BinanceSocketClient();
  socketClient.Spot.SubscribeToOrderBookUpdates("BTCUSDT", data => {
	// Handle data
  });
}
```
Subscribe like this:
```csharp
private BinanceSocketClient _socketClient = new BinanceSocketClient();

// .. rest of the class

private void SomeMethod()
{
  _socketClient.Spot.SubscribeToOrderBookUpdates("BTCUSDT", data => {
	// Handle data
  });
}

```