# Allowing untrusted fonts for campaigns

The Windows operating system offers the ability to block untrusted font files. The Nexthink software agent uses an open-source font family optimized for computer screens to render campaign text.

<figure><img src="https://268444917-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FxJSUDk9NTtCHYPG5EWs3%2Fuploads%2Fgit-blob-eec048ebf5978d2616c47c1fae24818b3a4f10ab%2Fnxcheseaux-20230418-152723-2x-20230418-132723.png?alt=media" alt="" width="544"><figcaption><p>Campaign preview using the web interface</p></figcaption></figure>

Previewing campaigns from the web interface always uses the correct font. If you suspect campaigns are not always rendered using the official font family:

* Connect to a device.
* Open the local log file in the `%ProgramData%\Nexthink\Logs\User` folder, labeled something like `nxtray*.log` where the `*` represents a combination of the user SID and a sequence of numbers.
* Search for lines containing `QML FontLoader: Cannot load font:` or something similar.

Here is an extract of a log file:

```
[2023-04-13 17:56:51.160][ 7736][10028][W][`anonymous-namespace'::qtMessageHandler] [Qt] qrc:/qml/Constants.qml:157:39: QML FontLoader: Cannot load font: "qrc:/NotoSans-Regular.ttf"
[2023-04-13 17:56:51.160][ 7736][10028][W][`anonymous-namespace'::qtMessageHandler] [Qt] qrc:/qml/Constants.qml:153:39: QML FontLoader: Cannot load font: "qrc:/NotoSansSC-Regular.otf"
[2023-04-13 17:56:51.160][ 7736][10028][W][`anonymous-namespace'::qtMessageHandler] [Qt] qrc:/qml/Constants.qml:149:39: QML FontLoader: Cannot load font: "qrc:/NotoSansJP-Regular.otf"
```

To allow the `nxtray.exe` process to load untrusted fonts:

1. Add a registry key on all devices in `Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options` and name it `nxtray.exe`.
2. In `Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\nxtray.exe` add a new QWORD (64-bit) value named `MitigationOptions` with the hexadecimal value of `2000000000000`.
3. Restart Windows to apply the changes.