1. Open up the Terrain Toolbox window in Windows -> Terrain -> Terrain Toolbox
2. Select the Create New Terrain Tab
3. View the Options section
4. Observe the directory that currently exists in the Terrain Data Directory Field
5. Click on the three dots next to the TerrainData Directory field
6. On the pop up window that appears, select cancel

Actual Results: The directory field is cleared and empty
Expected results: The previously set directory would stay set

Note: This happens on all directory fields within the Terrain Toolbox. Known existing fields are:
1. Terrain Utilities -> Export Splatmaps
2. Terrain Utilities -> Export Heightmaps
3. Create New Terrain -> TerrainData Directory