Reproduction steps:
1. Open the attached “IN-101923.zip” project
2. Open the “DropdownField Error Scene” Scene (Assets > EmptyDropdown > Scenes)
3. Enter Play mode
4. Click “Clear Choices” button
5. Toggle the “Toggle Enable Dropdown” property
6. Click on the Choices dropdown
7. Observe the Console

Expected result: No errors
Actual result: “ArgumentOutOfRangeException: Index was out of range. “ is thrown

Reproducible with: 6000.0.49f1, 6000.1.4f1, 6000.2.0b2
Couldn’t test with: 2022.3.62f1 (Could not downgrade)

Reproducible on: Windows 11, macOS 15.3.2 (M3 Max), Ubuntu 22.04
Not reproducible on: no other environment tested

Note:
- Does not reproduce when the same functionality is implemented as an Editor window. This can be observed going Error > Dropdown Error Test (from the top bar) and performing the same reproduction steps without entering Play mode