# Bug: Inserting block instance in Rhino 8 creates corrupted state

**URL:** <https://discourse.mcneel.com/t/bug-inserting-block-instance-in-rhino-8-creates-corrupted-state/211340>\
**Category:** Rhino\
**Tags:** windows\
**Created:** [October 23, 2025, 6:12am UTC](https://discourse.mcneel.com/t/bug-inserting-block-instance-in-rhino-8-creates-corrupted-state/211340 "2025-10-23T06:12:00Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![gyorgy.bozoki](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/gyorgy.bozoki/32/704592_2.png) [@gyorgy.bozoki](https://discourse.mcneel.com/u/gyorgy.bozoki)\
**Post date:** [October 23, 2025, 6:12am UTC](https://discourse.mcneel.com/t/bug-inserting-block-instance-in-rhino-8-creates-corrupted-state/211340/1 "2025-10-23T06:12:00Z")

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I ran into an issue in Rhino 8, where inserting a block instance into a top-level model when that block definition is also part of another block definition creates a broken state.

 ![Block-Issue 2025-10-23](https://global.discourse-cdn.com/mcneel/uploads/default/original/4X/3/9/8/3989ee57760b29e5e8610e5201338d99e345f1ac.png)

As the screenshot shows, the block instance is inserted and it shows up in the views, but:

- it doesn’t appear in the block definition list
- it doesn’t have the gumball
- no operation works on it (move, rotate, etc.)
- it doesn’t get saved into the file during save (or at least it doesn’t show up after a load)
- it gets diagnosed as a valid object

To reproduce:

1. Open `Block-Issue.3dm`
2. Use the `Insert` command to insert a new instance of the `Small-Ellipsoid.3dm` file
3. Observe that selecting the newly-inserted block instance cannot be transformed
4. After saving the file and then loading it back, the inserted block instance is missing

The main model contains instances of `Complex-Block.3dm` which contains instances of `Cube-With-Ellipsoid.3dm` which, in turn, contains instances of `Cube.3db` and `Small-Ellipsoid.3dm`. When inserting a new instance of `Small-Ellipsoid` at the top level, it should be listed as a linked block definition to the top-level model, not just as a dependency of `Complex-Block`.

Any advice would be appreciated - I use block instances a lot and the actual model has many nested, linked block definitions, so this is a blocker for me at this point, because I need to insert the same block instance at multiple levels of the model. (The attached model is just a minimal repro for the problem.)

[Block-issue.7z](https://discourse.mcneel.com/uploads/short-url/nwJWP0jSDuIJ4vJNjK4atDbOufV.7z) (646.3 KB)

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<div class="post-metadata">

**Author:** ![gyorgy.bozoki](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/gyorgy.bozoki/32/704592_2.png) [@gyorgy.bozoki](https://discourse.mcneel.com/u/gyorgy.bozoki)\
**Post date:** [October 23, 2025, 2:16pm UTC](https://discourse.mcneel.com/t/bug-inserting-block-instance-in-rhino-8-creates-corrupted-state/211340/2 "2025-10-23T14:16:21Z")

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As a workaround, it seems to work if I add the blocks to the top-level model in a different order - adding the blocks with no nested blocks inside and then adding the more complex ones seems to work - all the block definitions show up in the block list and they can all be edited as expected.

This works, but it’s far from ideal, since it means a complex model must be created from simplest components to more complex ones, with no simple components added at all at a later time.

This bug is also present in Rhino 7.

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**Author:** ![gyorgy.bozoki](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/gyorgy.bozoki/32/704592_2.png) [@gyorgy.bozoki](https://discourse.mcneel.com/u/gyorgy.bozoki)\
**Post date:** [October 24, 2025, 5:09pm UTC](https://discourse.mcneel.com/t/bug-inserting-block-instance-in-rhino-8-creates-corrupted-state/211340/3 "2025-10-24T17:09:21Z")

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Can anyone from McNeel please confirm if this is a bug?

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**Author:** ![Japhy](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/japhy/32/487647_2.png) [@Japhy](https://discourse.mcneel.com/u/Japhy)\
**Post date:** [October 25, 2025, 11:49am UTC](https://discourse.mcneel.com/t/bug-inserting-block-instance-in-rhino-8-creates-corrupted-state/211340/4 "2025-10-25T11:49:01Z")

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> [@gyorgy.bozoki](#):
>
> To reproduce:
> 
> 1. Open `Block-Issue.3dm`
> 2. Use the `Insert` command to insert a new instance of the `Small-Ellipsoid.3dm` file
> 3. Observe that selecting the newly-inserted block instance cannot be transformed
> 4. After saving the file and then loading it back, the inserted block instance is missing
> 
> The main model contains instances of `Complex-Block.3dm` which contains instances of `Cube-With-Ellipsoid.3dm` which, in turn, contains instances of `Cube.3db` and `Small-Ellipsoid.3dm`. When inserting a new instance of `Small-Ellipsoid` at the top level, it should be listed as a linked block definition to the top-level model, not just as a dependency of `Complex-Block`.

Hi Gyorgy Bozoki,

I haven’t been able to repeat with these steps. I’ll make a small video, I might be doing something wrong.

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<div class="post-metadata">

**Author:** ![gyorgy.bozoki](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/gyorgy.bozoki/32/704592_2.png) [@gyorgy.bozoki](https://discourse.mcneel.com/u/gyorgy.bozoki)\
**Post date:** [October 25, 2025, 4:10pm UTC](https://discourse.mcneel.com/t/bug-inserting-block-instance-in-rhino-8-creates-corrupted-state/211340/5 "2025-10-25T16:10:40Z")

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Thank you for your reply @Japhy . Your video shows exactly what I’m doing, except I can readily reproduce this problem in both Rhino 7 and 8. (In your video, you used Embedded while I’m using Linked - I wonder if this is where the problem is.)

Here’s a video of me doing the same in Rhino 8:

Here’s also another set of files I made in Rhino 7, showing the same problem:

[Block-Issue-v7.7z](https://discourse.mcneel.com/uploads/short-url/dbcdsQBjbbUDgNmn0vSTiV7Atvm.7z) (79.8 KB)

There are 2 top-level models in this file, `ComplexModel.3dm` and `ComplexModel-alt-order.3dm`. In the alt-order file, I first added a reference to the `Sphere` block and added the `Cube-with-sphere` block after. This way, the `Sphere` block is still valid, it shows up in Block Manager and can be edited as normal; the same for `Cube-with-sphere` (which contains `Sphere`.)

In the other file, I did the same as in Rhino 8 - I added the multi-level block definition first and then `Sphere` and it’s broken.

Can you think of anything that may cause this? Is there any diagnostic information I could give you to troubleshoot? I don’t believe I made drastic changes to Rhino settings, outside of configuring the appearance of the application.

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**Author:** ![wim](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/wim/32/747482_2.png) [@wim](https://discourse.mcneel.com/u/wim)\
**Post date:** [October 27, 2025, 8:40am UTC](https://discourse.mcneel.com/t/bug-inserting-block-instance-in-rhino-8-creates-corrupted-state/211340/6 "2025-10-27T08:40:46Z")

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Hi Gyorgy -

> [@gyorgy.bozoki](#):
>
> I ran into an issue in Rhino 8, where inserting a block instance into a top-level model when that block definition is also part of another block definition creates a broken state.

I’ve put this issue on the list as [RH-90166](https://mcneel.myjetbrains.com/youtrack/issue/RH-90166) Block: Unable to Transform Linked Instance  
-wim