Search Issue Tracker
By Design
Votes
0
Found in
2019.4
2020.3.8f1
2020.3.25f1
2021.1.0a2
2021.2
2022.1
2022.2
Issue ID
1401765
Regression
Yes
Prefab "Duplicate identifier" errors when importing Prefab in different Editor version than it was created
Reproduction steps:
1. Open the attached project "prefab"
2. In Project Window open the "Assets" folder and find the file "street"
3. Right-click the "street" file and press Reimport
Expected result: Prefab is imported without any errors
Actual result: Console errors: Duplicate identifier -758073206. File: "".
Duplicate identifier -758073096. File: "Assets/street.prefab".
Reproducible with: 2019.4.37f1, 2020.3.8f1, 2020.3.32f1, 2021.1.0a2, 2021.1.28f1, 2021.2.19f1, 2022.1.0b14, 2022.2.0a9
Not reproducible with: 2020.3.0f1, 2020.3.7f1, 2021.1.0a1
Add comment
All about bugs
View bugs we have successfully reproduced, and vote for the bugs you want to see fixed most urgently.
Latest issues
- Errors are logged when importing an asset at a path with Firebase
- Entering too big of a number in 2D Renderer Lightmode Tags freezes the Editor
- Crash on GUIManager::DoGUIEvent when focusing on the Game view window on a specific project
- Asset creation in the Project Browser is not always undone/inconsistent when the undo shortcut is pressed right after creating an asset
- JobTempAlloc memory leak warning is thrown when the Player is shut down
Resolution Note:
We have scanned through the content of the problematic prefab file and it is indeed corrupted and as such cannot be instantiated.
As the error log states, there are a lot of objects in the file that has identical FileIds and these are supposed to be unique within the same single file.
We sometimes see problems like this if the prefab was merged, for instance via a source control system. We recommend never to merge Unity files as there is no merge tool able to handle how rigid the structure of the files is. We are not aware of any mechanism where a prefab can be corrupted by Unity itself.
There is no way to fix the content of this prefab except for manually modifying the file Ids for every single object, but that is very time confusing and hard to get right.
I would recommend that you re-create the prefab from scratch.