Question: I've just setted up a fresh Symfony 4 project but when I navigate to the "public" folder the webprofiler shows up with the following message: 

```
An error occurred while loading the web debug toolbar. Open the web profiler.

```

When I click on "Open the web profiler" I get the following error: 

```
Error 404, Object not found

```

The path which is not found is in this case:

```
http://localhost/test-project/public/_profiler/4d2f65

```

Could anyone help me fix this issue?

Answer: 
If you are setting up a Symfony4/Flex app from scratch, it might not have the profiler installed.

```
composer require profiler --dev

```

You may also need to follow the [webserver-config](https://symfony.com/doc/current/setup/web_server_configuration.html) to enable mod\_rewrite in Apache, or the equivalent in Nginx.
Test it with a server.

```
php -S localhost:8000 -t public/

```

After that navigate to: 

<http://localhost:8000/_profiler>