How to reproduce:
1. Create a new project
2. Import the HD RP package from the Package Manager
3. In the Hierarchy window create a new GameObject
4. Add the 'Decal Projector' Component to the newly created GameObject
5. Duplicate the GameObject at least 128 times

Expected result: the GameObject is duplicated successfully
Actual result: GameObject is duplicated but an error occurs: 'IndexOutOfRangeException: Index was outside the bounds of the array'

Reproducible with: 10.0.0-preview.27 (2020.2.0b7, 2021.1.0a1)
Not reproducible with: 4.10.0-preview (2018.4.28f1), 7.3.1 (2019.4.12f1), 8.2.0 (2020.1.9f1), 9.0.0-preview.54 (2020.2.0b6)

Notes:
1. the same issue occurs when adding 129 'Decal Projector' Components to a single GameObject
2. The error is thrown again when building