Since updating to 2019.4.4 we have been having an issue where any code change results in tons of prefabs reimporting. This has slowed us down immensely as it takes a few minutes to do this.
You can literally just add a comment to any script, save, and click back on the editor. And it will reimport hundreds of prefabs for no reason.
I have looked into which prefabs it is reimporting and which it isn’t. The only common thread I can tell is
- All the prefabs that reimport have several sub objects inside them with 3D geometry
- Prefabs that were imported directly from FBX do not reimport
- Prefabs that have no 3D geometry at all do not reimport.
I’ve used OnPreprocessAsset in order to see what information I can get about this, but beyond getting a list of the assets being imported I can’t see anything useful in there.
This is what is in the editor log:
[MODES] Loading mode Default (0) for mode-current-id-GameName
Mono: successfully reloaded assembly
- Completed reload, in 6.276 seconds
Platform modules already initialized, skipping
Start importing Assets/Content/Asset1.prefab using Guid(936b5ce92c8989446a91ca27a4f6cc37) Importer(-1,00000000000000000000000000000000)
Done importing asset: ‘Assets/Content/Asset1.prefab’ (target hash: ‘98681aa5cc104a34a05a26eae22a3ee0’) in 0.114920 seconds
Start importing Assets/Content/Asset2.prefab using Guid(936b5ce92c8989446a91ca27a4f6cc37) Importer(-1,00000000000000000000000000000000)
Done importing asset: ‘Assets/Content/Asset2.prefab’ (target hash: ‘98681aa5cc104a34a05a26eae22a3ee0’) in 0.114920 seconds
And then hundreds more similar lines for each prefab it reimports.
What is causing this? How can I fix it? Having the team wait minutes after each code change is killing us.