# ActiveReportsJS: Troubleshooting

Learn how to solve common problems that you can face using ActiveReportsJS

## Content

This page enumerates the most common problems you can face using ActiveReportsJS and offers solutions.

### Report displays differently in the browser and in the exported PDF document

Ensure the proper [Fonts configuration](/activereportsjs/docs/v6.1/GettingStarted/FontConfiguration)

### When my application uses Bootstrap and ActiveReportsJS viewer, the report output does not match the same in the Standalone Designer application.

`Bootstrap` sets the [line-height](https://developer.mozilla.org/en-US/docs/Web/CSS/line-height) value for all HTML elements to `1.5`, and it affects the report output. The best way to fix it is to replace this value with `normal`. One way to achieve that is using the [Bootstrap Theming](https://getbootstrap.com/docs/4.6/getting-started/theming/#importing) feature and overwrite the `line-height-base` variable's value before importing the `reboot` module in the custom SCSS style declaration:

```scss
$line-height-base: normal;
@import "../node_modules/bootstrap/scss/reboot";
```

Alternatively, you could isolate the ActiveReportsJS Report Viewer component so that it would not be altered by `Bootstrap` styles at all, but the specific method to achieve that depends on the application's architecture.

### Data Requests work fine in the Design tab but fail in the Preview tab of the Standalone Designer application

If you can create and validate a [dataset](/activereportsjs/docs/v6.1/ReportAuthorGuide/Databinding#data-set-configuration) in the Design tab but in the Preview tab the `Data processing error` occurs, then ensure that the end-point allows CORS requests.

### How can I debug data requests in the standalone designer application?

Create a file called `config.json` in the standalone designer application's folder:

* Windows : %AppData%\ActiveReportsJS Designer
* MacOS: \~/Library/Application Support/ActiveReportsJS Designer
* Linux: \~/.config/ActivereportsJS Designer

And add the following content into that file.

```json
{
  "debug":true
}
```

Restart the standalone designer application and use `Ctrl + Shift + F12` hotkey for Windows and `⌘ + Shift + F12` (or, if your keyboard does not use the standard functions keys,  `⌘ + fn+ Shift + F12`) for Mac to open the `Developers Tools`. Use the `Network` tab to monitor data requests.
Here is the screenshot for debugging the data request of the [Doughnut Chart Demo Report](/activereportsjs/demos/Reports/PieChart/purejs)

![](https://cdn.mescius.io/document-site-files/images/e637becb-8cbc-4561-bac1-84462097b057/developer-guide/debug-eud.png)