Reproduction steps:
1. Open the user's attached project and Scenes/SampleScene scene
2. Navigate to Window/Asset Management/Addressables/Groups and select Build/New Build/Default Build Script
3. Select Tools/Check for Content Update Restrictions and select the bin from the previous step
4. Observe Console window

Expected result: ArgumentNullException appears and the Check for Content Update Restrictions window does not appear
Actual result: There are no errors and the Check for Content Update Restrictions window appears

Reproducible with: 1.17.13 - 1.17.17 (2019.4.25f1, 2020.3.6f1, 2021.1.5f1, 2021.2.0a14)
Not reproducible with: 1.16.19 - 1.17.6-preview (2019.4.25f1, 2020.3.6f1, 2021.1.5f1, 2021.2.0a14)
Could not test with: 2018.4 (could not downgrade)