Unity Issue Tracker - OnPostprocessPrefab modifies the source Prefab when fields are edited outside Prefab Mode

Won't Fix

Won't Fix in 6000.2.X

Votes

0

Found in

2021.3.45f1

2022.3.50f1

6000.0.23f1

6000.1.0a7

6000.2.0a1

Issue ID

UUM-84465

Regression

No

OnPostprocessPrefab modifies the source Prefab when fields are edited outside Prefab Mode

Serialization

-

Oct 15, 2024

How to reproduce:
1. Open the attached “IN-86620” project
2. Select the “TestPrefab” in the Project window
3. Observe the values of the “Test Component” script In the Inspector (Field 1: “error”, Field 2: “10”)
4. Double-click “TestPrefab” to open Prefab Mode
5. Observe the values of the “Test Component” script (Field 1: “hello”, Field 2: “10”)
6. Exit Prefab Mode
7. Select the “TestPrefab” and change the value of “Field 2” (for example, to “1”)
8. Double-click “TestPrefab” to open Prefab Mode again
9. Observe the values of the “Test Component” script

Expected result: The value of “Field 1” is “hello”
Actual result: The value of “Field 1” is “error”

Reproducible in: 2021.3.45f1, 2022.3.50f1, 6000.0.23f1

Reproducible on: Windows 11, macOS 14.6.1 (Intel)
Not reproducible on: No other environments tested

Note: Selecting the three dots (⁝) menu and pressing “Reset” on the “Test Component” script changes the script to its initial state (before reproduction steps)