Curve object in use as curve bevel object is removed by Purge Unused Data operator if it's not in the scene #79
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Original bug report: https://projects.blender.org/blender/blender/issues/157300
System Information
Operating system: Windows-10-10.0.19045-SP0 64 Bits
Graphics card: NVIDIA GeForce RTX 2070 SUPER/PCIe/SSE2 NVIDIA Corporation 4.6.0 NVIDIA 591.44 Opengl Backend
Blender Version
Broken: version: 5.2.0 Alpha, branch: main, commit date: 2026-04-12 18:23, hash:
398b27ad1b8aWorked: -
Short description of error
If a curve object is used as the bevel object on another curve, and the bevel object is then unlinked from the scene, the bevel object will be removed at some point even though it is in use. Depending on whether the object was in a collection when it was unlinked, it will either be: removed immediately, after saving and reverting the file, or by using the Purge Unused Data operator from the File> Cleanup menu.
My guess (from looking at the Outliner) is that when the curve object is chosen as the bevel object from the selection list, the user count of the curve object isn't increased, so if the object isn't used elsewhere, it is removed. If this is the underlying cause, I imagine there are other places this happens. I tested choosing the same object as the Taper Object on the curve and it also didn't increase the user count.
Exact steps for others to reproduce the error
Using the attached file where the 'Profile' object is set as the Bevel Object on the 'BezierCurve':
The curve's bevel has immediately disappeared. It now has zero users and will be removed from the file after saving and re-opening or purging data.
This is almost understandable as unlinking is a bit similar (from a user perspective) to deleting and might go unnoticed as a bug.
A clearer example is when you unlink the collection the object is in instead as the bevel doesn't immediately disappear:
The bevel will disappear from the curve.
Report is clear
LLM Reasoning
Got it, let's see. The question is whether the bug report clearly describes the issue. I need to check the clarity of the text and steps to reproduce.
First, the title is clear: "Curve object in use as curve bevel object is removed by Purge Unused Data operator if it's not in the scene". Then the body has a short description explaining the error—when a curve is used as a bevel object and unlinked, it gets removed even though it's in use. The steps to reproduce are detailed: using an attached file (even though we don't have it, but the steps are there), unlinking the profile object or its collection, then purging data. The explanation of user count is also included.
The steps are clear: 1. Unlink Profile object, bevel disappears immediately. Or 2. Unlink collection, clear fake user, purge unused, bevel disappears. So the description and reproduction steps are present and understandable. Even with some system info, we ignore that. The text is clear enough to understand what's happening. So the answer should be Yes.
JSON Data
{
"llm_judgement": true,
"processing_time": 15.380168
}
Report is specific
LLM Reasoning
Got it, let's figure out if this bug report is specific or generic. The question says specific is about a particular issue, like crashing with a specific feature. Let's look at the report.
The title mentions "Curve object in use as curve bevel object is removed by Purge Unused Data operator if it's not in the scene". The body describes exactly when this happens: using a curve as a bevel object, unlinking it, then purging unused data removes it. There are exact steps to reproduce, like unlinked collection and purge. So it's about a specific scenario—using a curve as a bevel object and how purging affects it. That's a specific issue because it's tied to that particular use case (bevel object) and the operator (Purge Unused Data). Generic would be vague, like "crashing while rendering" without specifics. Here, the steps are detailed, so it's specific.
JSON Data
{
"llm_judgement": true,
"processing_time": 13.825136
}
Report flagged as NOT a duplicate by LLM
Blender crashes when unlinking indirectly used objects from the Outliner
https://projects.blender.org/blender/blender/issues/145681
System Information
Operating system: Windows-10-10.0.19045-SP0 64 Bits
Graphics card: NVIDIA GeForce RTX 4080 SUPER NVIDIA Corporation NVIDIA 566.36 Vulkan Backend
Blender Version
Broken: version: 4.5.1 LTS, branch: blender-v4.5-release, commit date: 2025-07-29 05:31, hash:
b0a72b245dcfBroken: version: 4.5.2 LTS, branch: blender-v4.5-release, commit date: 2025-08-19 15:00, hash: ab25eae04993, type: Release
Worked: (newest version of Blender that worked as expected)
Short description of error
Blender crashes when unlinking indirectly used objects from the Outliner
Exact steps for others to reproduce the error
CollectionObjectBevel ObjectBevel Objectis not inside the previously created collectionCollectionBevel Objectas Bevel Object to the first bezier curveObjectAsset.blendand close itAsset.blendCollectionBevel Objectshowing up under the categoryObjectsCannot delete object 'XXX' from scene 'Scene', indirectly used objects need at least one userin the status barBevel Objectand choose UnlinkThe error here is probably that indirectly linked objects should never show under the Unused Data Outliner, since they are effectively being used by the instance. Unlinking them should not be allowed, or if it is it should probably fail.
See attached video of procedure. Example Asset.blend provided
LLM Reasoning
Got it, let's analyze these two bug reports. First, look at the descriptions and steps to reproduce.
Bug report 1 is about a curve object used as a bevel object being removed by Purge Unused Data when unlinked. The key points: using a curve as bevel, unlinking (either object or collection), then purge removes it because user count isn't increased.
Bug report 2 is about Blender crashing when unlinking indirectly used objects (like the bevel object) from the Outliner's Unused Data section. Steps involve linking a collection with a curve that has a bevel object, then trying to unlink the bevel object which causes a crash.
The core issues are different: one is about data being purged incorrectly (report 1), the other is a crash when unlinking (report 2). The first is about incorrect user count leading to purge, the second is a crash during unlink. So they're not the same issue.
JSON Data
{
"llm_judgement": false,
"processing_time": 17.348598000000003,
"duplicate_report_number": "145681"
}
Report flagged as NOT a duplicate by LLM
Curve Taper / Bevel object can not be removed
https://projects.blender.org/blender/blender/issues/22730
%%%Blender 2.52 SVN29902 Windows XP Pro 32bit
Intel E8400 Nvidia 8600GT 4GB ram
If you make an entry in Curve Properties>Geometry> Taper Object or Bevel Object
it is not possible to remove the Taper or Bevel Object entry. The only option is to use one of the other objects in the object list but not remove it altogether.
This also happens in the 2.5 alpha 2 release
Many thanks%%%
LLM Reasoning
Got it, let's analyze these two bug reports. First, look at the descriptions and steps to reproduce.
Bug report 1 is about a curve object used as bevel/taper being removed by Purge Unused Data when unlinked, because the user count isn't increased. The steps involve unlinking the bevel object or its collection, then purging data, which removes the bevel effect.
Bug report 2 is about not being able to remove the Taper/Bevel Object entry—only replace with another object, can't clear it. So the issue here is that you can't delete the reference, whereas bug 1 is about the object being removed when unlinked (user count issue).
The core issues are different: one is about unintended removal via purge due to user count, the other is about inability to remove the entry at all. So they're not the same. Therefore, the answer is No.
JSON Data
{
"llm_judgement": false,
"processing_time": 14.100896,
"duplicate_report_number": "22730"
}
Report flagged as NOT a duplicate by LLM
Known Issue - Not A Bug: Re-doing the Purge of unused linked data does not delete again the affected linked data
https://projects.blender.org/blender/blender/issues/117303
System Information
Operating system: N/A
Graphics card: N/A
Blender Version
Broken: current
mainWorked: ???
Short description of error
Undoing and redoing a 'Purge unused data' operation properly re-delete the affected unused local IDs, but not the linked ones.
Exact steps for others to reproduce the error
Using linked_data_purge.blend:
Collectionfrom the scene.Orphanedview of the Outliner.LLM Reasoning
Got it, let's analyze these two bug reports. First, look at the descriptions and steps.
Bug report 1 is about a curve object used as a bevel object being removed by Purge Unused Data when unlinked. The key points: bevel object (curve) gets removed even though in use, steps involve unlinking the object or collection, then purging.
Bug report 2 is about purging linked data—when you undo/redo purge, local IDs are re-deleted but linked ones aren't. Steps involve unlinking a collection, disabling fake user, purging, then undo/redo.
The first bug is about a specific case (curve bevel object) being removed by purge when unlinked. The second is about the behavior of purge with linked data during undo/redo. Are they the same issue? Let's check the core problem. Bug 1 is about an object in use (bevel) being purged, bug 2 is about linked data not being re-purged on redo. Different scenarios: one is a specific object type (curve bevel) and its user count, the other is linked vs local IDs during undo/redo purge. So they are not the same issue. Therefore, answer is No.
JSON Data
{
"llm_judgement": false,
"processing_time": 17.914188999999997,
"duplicate_report_number": "117303"
}
Report flagged as NOT a duplicate by LLM
Unparenting a mesh object from a curve removes Curve modifier.
https://projects.blender.org/blender/blender/issues/114655
System Information
Operating system: Windows-10-10.0.22631-SP0 64 Bits
Graphics card: NVIDIA GeForce RTX 3080 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 546.01
Blender Version
Broken: version: 3.6.5, branch: blender-v3.6-release, commit date: 2023-10-16 14:30, hash:
cf1e1ed46b7eWorked: (newest version of Blender that worked as expected)
This seems intentional, see 2babbb59b9, but is very intransparent (might require an additional option?)
Short description of error
[Please fill out a short description of the error here]
unparenting a mesh object from a curve removes Curve modifier.
Exact steps for others to reproduce the error
[Please describe the exact steps needed to reproduce the issue]
[Based on the default startup or an attached .blend file (as simple as possible)]
LLM Reasoning
Got it, let's analyze these two bug reports. First, look at the descriptions and steps.
Bug report 1 is about a curve object used as a bevel object being removed by Purge Unused Data when unlinked. The key points: curve as bevel object, unlinking (or purging) removes it even though in use.
Bug report 2 is about unparenting a mesh from a curve removing the Curve modifier. Steps involve making a curve, plane with Array and Curve modifiers, parenting to curve, then unparenting—modifier gets removed.
These are different issues. Report 1 is about bevel objects being purged, report 2 is about Curve modifier removal on unparenting. So they're not the same. The answer should be No.
JSON Data
{
"llm_judgement": false,
"processing_time": 13.340171,
"duplicate_report_number": "114655"
}
Report flagged as NOT a duplicate by LLM
Statistic display issue with curve object selected
https://projects.blender.org/blender/blender/issues/147702
System Information
Operating system: Windows-10-10.0.19045-SP0 64 Bits
Graphics card: NVIDIA GeForce RTX 3070 NVIDIA Corporation NVIDIA 580.97 Vulkan Backend
Blender Version
Broken: version: 5.0.0 Beta, branch: blender-v5.0-release, commit date: 2025-10-08 23:50, hash:
43654059ba71Worked: (newest version of Blender that worked as expected)
Short description of error
Exact steps for others to reproduce the error
LLM Reasoning
Got it, let's analyze these two bug reports. First, look at the descriptions and steps.
Bug report 1 is about a curve object used as a bevel object being removed by Purge Unused Data when unlinked. The issue is with user count not increasing, leading to unintended removal.
Bug report 2 is about statistic display for curve objects—when selected, stats show only object count instead of spline/vertex info, and this changes when the curve has evaluated mesh.
These are completely different issues: one is about data management (user count, purge) and the other is about UI statistics display. So they're not duplicates. The answer should be No.
JSON Data
{
"llm_judgement": false,
"processing_time": 13.830452000000001,
"duplicate_report_number": "147702"
}