Bug [Worker0] Tried select unknown importer for id '-2'

After updating Unity to 2021.2 (currently .7f) I often see strange errors in the console:

Code (CSharp):

1. [Worker0] Tried select unknown importer for id '-2'

I am not sure what causes this, but I noticed it happens when I open directory with prefabs and it seems somehow related to prefab preview generation.

Also I see it's not only me with this problem, however I am not sure what to do to reliably reproduce it.
Is this known issue or can I get some hints how to find the source of the problem?

 

I have the same problem (2021.2.6f1) and would like to know how to suppress it in Editor, because it's so annoying to see.

 

I also have this problem since updating yesterday to 2021 version after I was having crash issues with the 2020 LTS version. It happens to me specifically when opening prefabs.

 

same here.

it's really really annoying !

 

Same issue... in 2021.2.12

 

I think this error comes only from assets made before upgrade, my wild guess is that it might be fault of shader graph, but we need more info. If any of you can provide some observations please do it.

 

I have the same error. I get this error whenever I change a prefab, when leaving the playmode in the editor and also when doing changes to scripts.
It has nothing to do with old prefabs from older projects/unity versions, I used the same version 2021.2.10f1 for this new project the entire time and out of nowhere this error started to appear regulary.

In the AssetImportWorker0.log I have found the following message:

Received Import Request.
Time since last request: 20.002823 seconds.
path: Assets/Prefabs/MyPrefab.prefab
artifactKey: Guid(d1eabf04429ee4dbab3d837110ba32b2) Importer(815301076,1909f56bfc062723c751e8b465ee728b)
Start importing Assets/Prefabs/MyPrefab.prefab using Guid(d1eabf04429ee4dbab3d837110ba32b2) Importer(815301076,1909f56bfc062723c751e8b465ee728b) Tried select unknown importer for id '-2' '00000000000000000000000000000000'
-> (artifact id: '187acfb6ad86dca4c8f66ffa2ae164b6') in 2.910410 seconds

I tried deleting library folder, deleting and recreating the prefab and much more but this error comes back all the time. I just wasted 2 hours of reverting project files back and forth but couldn't get rid of it.

Does anyone has send a bug report yet?

 

I don't think so I moved to new project and forgot a bit about this problem - do it if you have example assets that you can send in issue.
Nevertheless I have one more suspicion and it's shader graph, I think it might be related to the fact that some prefabs contain materials with broken(?) or old shaders. Still, this comes only from observation (only some prefabs are affected).

 

Ok, I just send a bug report with my project.

 

Please drop the issue link herer when it's accepted.

 

Yes, I will do that. Did you get the error in your new project again ?

 

Nope

 

Still no confirmation from unity...

 

I'm getting this error too, on 2021.2.13 with a custom ScriptedImporter that generates a model prefab. The model prefab itself seems unaffected, so I'm not really sure what's going wrong.

 

Maybe you can create a bug report too. Looks like mine is getting ignored...

 

I had to wait more than half months once, plus I don't think it will help - it will just put more stuff to process for them.

 

Ok, but It’s already more than a month now. The tickets I opened so far where all approved/closed in less then 2 weeks. At the other hand I never had to submit a project with them, so that may explain the difference. I could also image that because there is a new LTS-Version now, that the priority for bugs with older versions got reduced.

 

Sorry, I am dumb. I wanted to write 2 months

 

Ok, I didn’t know that this could take so long.

 

I'm also getting this error on one of my prefab... so i'm writing so I get notified whenever there is new info on this

 

The only way that I have found to work 100% is to re-create the prefab that causes the problem.

 

I have the same error on my project too and it seems to be related to the gizmo that I used for two empty object. I changed it to the default "None" settings and no more error. Go figure xD !

I got the answer from this japanese website, they have picture so it helped to find the problem xD ! https://baba-s.hatenablog.com/entry/2022/05/21/080000?utm_source=feed

 

If this this is the cause, that would be hilarious XD

Today I got an email from Unity-Support. They were not able to reproduce the bug and I had to send them a video with some more details.

EDIT: OMG this really seems to be it... Thank you for sharing this, I will add this to the bug report!
I used a gizmo on a child object and removing it, also removes the error.

 

Turned out that they actually know about this issue: https://issuetracker.unity3d.com/product/unity/issues/guid/1397386

The support requested a backport for 2021.3, it is being evaluated.

 

I have also been seeing this issue, and similar issues with the inspector and what appears to be the icon for the selected object. Below you can see (a single frame) where the icon flashes to a blank square, before changing to the default prefab icon.

If I don't lock the inspector then unity will automatically deselect the object and hide the inspector. I'm using unity 2022.1.2f1

 

If you are already using Unity 2022, you can upgrade to the newest version where this issue is fixed.

 

For me, it was an asset that was using those colored icons on their scripts to make them easy to find.

I'm still getting this, though:
[Worker0] Trying to get RenderBuffer with invalid antiAliasing (must be at least 1)

but this one is gone:
[Worker0] Tried select unknown importer for id '-2' '00000000000000000000000000000000'

after finding the scripts and setting their icons to None. Image taken from the Japanese post.

 

I'm also getting this error on my mac with unity version 2020.1.1f

 

I have now confirmed it with two projects. When I import in a project, a Unity Package that contains a prefab that has a GameObject with an icon assigned the error gets triggered.

Thank you @Deloriand!!!

 

I just triple checked every single game object in my prefab that has this bug, even going as far as setting them a "gizmo icon" and then setting back to "none"... and it didnt fix it... I dont have any with an icon... really wish i could find a solution for this

 

Hi, I just updated one of my projects to the 2021.3.3f1 and after cleaning some unused assets, I started getting this error message punctually appearing. I don't see any particular reasons, I'm only editing a simple prefab.

 

Hi @FireHawkX I'm not sure why you are getting the bug as you describe. However, just wanted to emphasize that in my case, the bug occurred only after IMPORTING an asset that contained a "problem" prefab, i.e. a prefab that has an icon set. In other words, if you just set and then unset an icon, it will not produce the problem, or fix it, if it's caused by something else.

In my case, one of the problem prefabs had the icon set deep inside the hierarchy of the model, which made it difficult to find. More specifically, the icon was set in one of the rig Transforms, i.e. inside the root hierarchy (root/pelvis/spine_01/... etc.).

 

I have some good news regarding to this problem and the current LTS-Version. The support did tell me that the developers are working on a fix (back port) for 2021.3.X now.

 

@MidnightGameDeveloper this is good news!

I saw in the issue notes:
"Seems to reproduce on the initial import upon opening the folder the prefabs are in. Once the prefabs are imported, the issue no longer reproduces and the prefabs seem to function correctly"

However, in my case the error message isn't thrown for every prefab I import, but just the ones that have an icon somewhere in their hierarchy. Also, it's not a one-time thing, it's every time I select the problem prefab.

So, I hope that the developers fix that too .

 

This is not the bug report that I have created, mine got closed as duplicate but I can still contact the support via my case. I have reported the issue in the way you described it, so yes I am also hoping that this is fixed as well .

 

thank you！！！！！

 

I've been getting this error message too, hope they port this fix to Unity 2021 LTS soon.

 

With the release of Unity 2021.3.7f1 this got finally fixed today!
https://unity3d.com/unity/whats-new/2021.3.7

 

I've been having this issue as well - and removing the gizmo (as mentioned in the japanese post) instantly fixed it. Using the gizmo again afterwards seems to no longer cause the bug either.

 

I've got the issue also, I'm in 2021.3.6- I see someone is suggested it's fixed in 2021.3.7- has that been everyone's experience too?

I have open bugs in Unity's Fogbugz from 2015 and 2016. At some point they closed all my bugs between 2017-2020. They are doing better in recent years I feel. it helps to have someone with a pro license report the bug.

 

I fixed it! I use Unity 2021.3.1f1, and I`am simply select all prefabs(error appeared when I open folder with my prefabs) and "Reimport (NOT "Reimport All")".

UPD.: After changes in prefab error appear again.

 

[Worker0] Tried select unknown importer for id '-2'
I solve the problem by putting the prefbs on a layer

 

I had the same problem when I go to the prefabs folder. Then I tried Deactivates and Activates my prefabs. Then the error disappeared but it reappeared when I changed the prefab.

 

I have this issue now that I upgraded a project from Unity2020.3.31 to Unity2020.3.42 (last one as of today). As some have mentionned, it's about script with custom icons. Very annoying.

 

Ughhh Unity

 

Have this error as well, just upgraded to 2020.3.43 today.

 

Error occurs in 2020.3.44
[Worker0] Tried select unknown importer for id '-2' '00000000000000000000000000000000'

 

that was exactly the solution for me , thank you

 

Error occurs in 2020.3.43 also
[Worker0] Tried select unknown importer for id '-2' '00000000000000000000000000000000'

 

I just have one question. What happens if I ignore these errors? This is just an editor error. so it shouldn't cause any issues in the built game right?
I'm still on 2022.1.6f1
My game is nearly done after a long time and I don't feel like upgrading unity yet. There are things that can go wrong after an update you know.