The targets array should not be used inside OnSceneGUI or OnPreviewGUI. Use the single target property instead errors are thrown on clicking on "Modifies the projector boundaries" button after resetting Decal projector.

/!\ you need to have Gizmos enabled in scene view for the error to repro.

Steps to repro:
1. Create a new HDRP Template Project.
2. Hierarchy > Right-click > Rendering > Decal Projector.
3. Inspector > Reset "Decal Projector" component.
4. Click on "Modifies the projector boundaries" button.

Actual Result:
The targets array should not be used inside OnSceneGUI errors are thrown in the console.

Expected Result:
No error in the console.

Reproducible in:
2020.2.0a7, 2020.1.0b6, 2020.1.0a23 with Package Version: 9.0.0, 8.0.1.

Environment:
Occurring on Windows 10 & Mac 10.15.

Stack trace:
The targets array should not be used inside OnSceneGUI or OnPreviewGUI. Use the single target property instead.
UnityEngine.GUIUtility:ProcessEvent (int,intptr,bool&)