How to reproduce:
1. Create a new project in any version from 2018.4.0f1 to 2020.2.0a13
2. Go to the Package Manager window and download Probuilder package
3. Open Probuilder Window and select "New Shape"
4. In Shape Selector field select stairs and in step field input huge number (for example 10000000)
5. Observe the Editor Window

Expected result: Probuilder generates stairs or does not let to input that big step count
Actual result: Unity Editor freezes

Reproducible with: 2018.4.23f1, 2019.4.0f1, 2020.1.0b11, 2020.2.0a13
Reproducible with package versions: 3.0.0, 4.3.0-preview.2

Notes:
1. Step count remains the same even after creating a new project and the user can not change "Steps" field before Unity editor freezes or crashes again
2. In newer versions Unity Editor shows "Hold on" table and still freezes
3. For some users it will crash instead of freeze