How to reproduce:
1. Open a new Unity project
2. Open the "SampleScene" scene
3. Select any GameObject from the Hierarchy
4. Click on the Preset icon at the right of the Transform component bar
5. On the "Select Preset" window, click on the "Save current to..." button to Save the Preset
6. Drag and drop the saved Preset file to the Inspector of the same GameObject
7. Click "Ok" on the dialogue, which informs that such component is already added

Expected behavior: Above-mentioned steps do not result in a Console error.
Actual behavior: "EndLayoutGroup: BeginLayoutGroup must be called first." error is thrown.

Reproducible with - 2018.1.0f1, 2018.1.9f2, 2018.2.0a4, 2018.2.6f1, 2018.3.0a1, 2018.3.0a10
Not reproducible with - 2018.1.0b13, 2018.2.0a3

Note: Presets were introduced in 2018.1 (therefore the issue is not tested on versions prior to 2018.1).