Error "NullReferenceException" is thrown when selecting folders from the folder panel or closing the folder panel with EditorUtility.OpenFolderPanel() in use

How to reproduce:
1. Open the project “IN_26551”
2. Open the “SampleScene” Scene in Scenes
3. Press the “Editor tools” → “Folder Test” → “Choose Folder”
4. Press the “Cancel” button

Expected result: no error in the Console
Actual result: “NullReferenceException” error in the Console

Reproducible with: 2021.2.0b15, 2021.3.16f1, 2022.1.0a14
Not reproducible with: 2021.2.0b14, 2022.1.0a15, 2022.2.2f1, 2023.1.0a25
Couldn’t test with: 2020.3.42f1 (couldn’t find created custom tool in the Editor Tools)
Fixed in: 2022.1.0a15

Reproducible on: Windows 10 Pro