How to reproduce:
1. Open the project "Localization_2019.3.1f1"
2. Open the scene "SampleScene"
3. Select the GameObject "RawImage" in the Hierarchy
4. Observe the Localize Texture component in the Inspector

Expected results: there is a Localised Asset Reference section in the Localize Texture component
Actual results: the Localised Asset Reference section is missing in the Localize Texture component

Reproducible with: 2019.3.1f1 (0.6.0)
Not reproducible with: 2020.1.0a23 (0.6.0)

Could not test with: 2017.4.37f1 because the Localization package is not supported, 2018.4.17f1 (0.2.3-preview) because the Localization package does not have some features

Notes:
1. The issue was introduced here: https://forum.unity.com/threads/localize-texture-empty-table-reference.803949/
2. The project was created by following 5 first steps from here: https://docs.unity3d.com/Packages/com.unity.localization@0.6/manual/QuickStartGuide.html
3. It is not reproducible with 2020.1 due to the added feature: generics are supported when serializing