Discord.Net/docs/faq/basics/client-basics.md

---
uid: FAQ.Basics.ClientBasics
title: Basic Questions about Client
---

# Client Basics Questions

## My client keeps returning 401 upon logging in!

> [!WARNING]
> Userbot/selfbot (logging in with a user token) is not
> officially supported with this library.
>
> Logging in under a user account may result in account
> termination!

There are few possible reasons why this may occur.

1. You are not using the appropriate [TokenType]. If you are using a
 bot account created from the Discord Developer portal, you should
 be using `TokenType.Bot`.
2. You are not using the correct login credentials. Please keep in
 mind that tokens is different from a *client secret*.

[TokenType]: xref:Discord.TokenType

## How do I do X, Y, Z when my bot connects/logs on? Why do I get a `NullReferenceException` upon calling any client methods after connect?

Your bot should **not** attempt to interact in any way with
guilds/servers until the [Ready] event fires. When the bot
connects, it first has to download guild information from
Discord in order for you to get access to any server
information; the client is not ready at this point.

Technically, the [GuildAvailable] event fires once the data for a
particular guild has downloaded; however, it's best to wait for all
guilds to be downloaded. Once all downloads are complete, the [Ready]
event is triggered, then you can proceed to do whatever you like.

[Ready]: xref:Discord.WebSocket.DiscordSocketClient.Ready
[GuildAvailable]: xref:Discord.WebSocket.BaseSocketClient.GuildAvailable

## How do I get a message's previous content when that message is edited?

If you need to do anything with messages (e.g. checking Reactions,
checking the content of edited/deleted messages), you must set the
[MessageCacheSize] in your [DiscordSocketConfig] settings in order to
use the cached message entity. Read more about it [here](xref:Guides.Concepts.Events#cacheable).

1. Message Cache must be enabled.
2. Hook the MessageUpdated event. This event provides a *before* and
 *after* object.
3. Only messages received *after* the bot comes online will be
 available in the cache.

[MessageCacheSize]: xref:Discord.WebSocket.DiscordSocketConfig.MessageCacheSize
[DiscordSocketConfig]: xref:Discord.WebSocket.DiscordSocketConfig
[MessageUpdated]: xref:Discord.WebSocket.BaseSocketClient.MessageUpdated