When a try:

```
sudo apt install elementary-sdk

```

it says

```
Unable to locate package elementary-sdk

```

It's a fresh install of loki. 

```
apt update 

```

give me a 404 error. 

```
Err:7 http://br.archive.ubuntu.com/ubuntu loki Release                                                                                                 
404  Not Found [IP: 200.236.31.4 80]

```