Selecting "Tree View" inside the UDW will result in the infinite spinner.

Steps to reproduce:
1. Clean installation of Ibexa DXP 3.2/3.3
2. Login into the back office as admin
3. Click on the "Browse" button.
4. From the top menu select "Tree View".

Result:
The tree view is never shown.

Expected result:
The Tree view is shown normally.