OTOY Forums

Hello
and happy new year!

I will try to explain first how the crash happens.
I am using templates to start the program with the defaults and add-ons I need.
So when the program loads I have different settings for cycles, ev and octane render.
All working as I need , so when i start no renderer is starting just plain eevee.
When I need cycles I load its template that loads the plugin too with all ui and plugins I wanted to load.
When I need Octane, again load its template with the setting I need a preselected Kernel and a world environment I had setup in shader editor. custom lights and custom default material.
I can go back and forth and the program unloads or reloads all my setups or add-ons specific to selected renderer.
When I start octane everything working fine! except if i select in "file/new/your custom startup Octanerender Startup (default)
or compositor and denoiser.
There the program crash.
I can send you my templates, but it only loads octane add-on and my custom interface...

Here is the crash raw log on the ATTACHMENT, with my startup template

PS. Seriously why we need these startups when we can make ours ?

Thanks in Advance

Konstantinos

A couple of points that may help clarify what’s happening.

If your startup files or templates were created with older Octane versions, that can definitely be a source of instability.
In 31.2 several things changed under the hood: some nodes were updated, others replaced or refactored, and some defaults were reset. In that sense, 31.2 is effectively a “fresh start”, and older startup scenes may reference data that no longer exists or behaves differently.

This is especially critical for:

• preconfigured World / Environment nodes

• Kernel presets

• Compositor / Denoiser setups

• custom default materials stored in the startup file

Loading those automatically at startup can trigger a crash if something is out of sync.

About the Octane startup templates:
they’re not meant to replace custom workflows, but to provide a safe, known-good baseline, especially for new or less experienced users. Having official startup options helps reduce misconfiguration and support issues, so they do serve a purpose — even if advanced users prefer their own setups.

Practical suggestion:
Try recreating your Octane startup template from scratch in 31.2, rather than reusing an older one. In many cases that alone resolves crashes like the one you’re describing.

If after that the crash still happens, then yes — sharing the template makes sense, because at that point it’s likely a specific edge case worth investigating.

Tried your suggestion, same behavior.
take alook at my uploaded files and @ this that i grabbed from system console :
register_class(...):
Info: Registering key-config preferences class: 'Prefs', bl_idname 'Blender' has been registered before, unregistering previous
Octane Addon Client is enabled
OctaneBlender.init: opts = {'server': None, 'port': None, 'cert': None}
192.168.50.102
Client connecting to localhost:50051
00:30.360 bpy.rna | WARNING unable to get Python class for RNA struct 'OctaneKernelOutputNode'
00:30.360 bpy.rna | WARNING unable to get Python class for RNA struct 'OctaneEditorWorldOutputNode'
00:30.375 bpy.rna | WARNING unable to get Python class for RNA struct 'octane_kernel_nodes'
00:30.407 bpy.rna | WARNING unable to get Python class for RNA struct 'OctaneDaylightEnvironment'
00:30.438 bpy.rna | WARNING unable to get Python class for RNA struct 'OctaneDirectLightingKernel'
00:30.672 bpy.rna | WARNING unable to get Python class for RNA struct 'OctaneLightIDBitValue'
00:30.672 bpy.rna | WARNING unable to get Python class for RNA struct 'OctaneLightIDBitValue'
00:30.672 bpy.rna | WARNING unable to get Python class for RNA struct 'OctaneLightIDBitValue'
00:30.672 bpy.rna | WARNING unable to get Python class for RNA struct 'OctaneLightIDBitValue'
Octane Ocio Management Update Start
Octane Ocio Management Update End. Time cost: 0.00 secs
192.168.50.102
Client connecting to localhost:50051

Thank you very much

OK ,removed everything not using templates, with blender 5.0.1 and after installing octane addon i saved preferences , vanila blender, and i tried your menu , instant crash.

I reloaded blender checked that addon is enabled in preferrences, not using any template i made, and its not crashing, give me some time, later I will try to create a template by modifing your startup .
will be back to you

Thank you

And last post,
I tried to work it out with the directory assets you have in octane.
That is I copy and rename startup_path_tracing.blend to startup.blend and placed in the 2 directories that blender use for templates and saving defaults.
c:\Users\dinos\AppData\Roaming\Blender Foundation\Blender\5.0\scripts\startup\bl_app_templates_user\Octane\
and
c:\Users\dinos\AppData\Roaming\Blender Foundation\Blender\5.0\config\Octane\
The crash happen with all 4 files you have in assets directory as i copied & renamed them, and placing in the above directories.
the preferences loads just the octane addon. in all cases.
and this is what i see in console using the template for direct lighting:

{
Octane Addon Client is enabled
OctaneBlender.init: opts = {'server': None, 'port': None, 'cert': None}
192.168.50.102
Client connecting to localhost:50051
01:44.281 bpy.rna | WARNING unable to get Python class for RNA struct 'OctaneKernelOutputNode'
01:44.281 bpy.rna | WARNING unable to get Python class for RNA struct 'OctaneRenderAOVOutputNode'
01:44.281 bpy.rna | WARNING unable to get Python class for RNA struct 'OctaneOutputAOVGroupOutputNode'
01:44.281 bpy.rna | WARNING unable to get Python class for RNA struct 'OctaneEditorWorldOutputNode'
01:44.281 bpy.rna | WARNING unable to get Python class for RNA struct 'OctaneEditorWorldOutputNode'
01:44.281 bpy.rna | WARNING unable to get Python class for RNA struct 'octane_composite_nodes'
01:44.281 bpy.rna | WARNING unable to get Python class for RNA struct 'octane_kernel_nodes'
01:44.281 bpy.rna | WARNING unable to get Python class for RNA struct 'octane_render_aov_nodes'
01:44.328 bpy.rna | WARNING unable to get Python class for RNA struct 'OctaneDaylightEnvironment'
01:44.328 bpy.rna | WARNING unable to get Python class for RNA struct 'OctaneTextureEnvironment'
01:44.344 bpy.rna | WARNING unable to get Python class for RNA struct 'OctaneDirectLightingKernel'
01:44.375 bpy.rna | WARNING unable to get Python class for RNA struct 'OctaneToonMaterial'
01:44.391 bpy.rna | WARNING unable to get Python class for RNA struct 'OctaneUniversalMaterial'
01:44.453 bpy.rna | WARNING unable to get Python class for RNA struct 'OctaneOutputAOVsOutputAOVGroup'
01:44.453 bpy.rna | WARNING unable to get Python class for RNA struct 'OctaneOutputAOVsRenderAOV'
01:44.453 bpy.rna | WARNING unable to get Python class for RNA struct 'OctaneOutputAOVsOutputAOV'
01:44.453 bpy.rna | WARNING unable to get Python class for RNA struct 'OctaneOutputAOVsOpenImageDenoise'
01:44.484 bpy.rna | WARNING unable to get Python class for RNA struct 'OctaneRenderAOVGroup'
01:44.547 bpy.rna | WARNING unable to get Python class for RNA struct 'OctaneMultiplyTexture'
01:44.547 bpy.rna | WARNING unable to get Python class for RNA struct 'OctanePolygonSide'
01:44.563 bpy.rna | WARNING unable to get Python class for RNA struct 'OctaneRaySwitch'
01:44.594 bpy.rna | WARNING unable to get Python class for RNA struct 'OctaneSunDirection'
01:44.594 bpy.rna | WARNING unable to get Python class for RNA struct 'OctaneLightIDBitValue'
01:44.594 bpy.rna | WARNING unable to get Python class for RNA struct 'OctaneLightIDBitValue'
Add Socket: [OctaneGroupTitle]Trace sets, Node[Daylight environment], NodeTree[World_Daylight_Environment]
Add Socket: Sun trace sets, Node[Daylight environment], NodeTree[World_Daylight_Environment]
Add Socket: Sky trace sets, Node[Daylight environment], NodeTree[World_Daylight_Environment]
Add Socket: Sun shadows exclude, Node[Daylight environment], NodeTree[World_Daylight_Environment]
Add Socket: Sun shadows reinclude, Node[Daylight environment], NodeTree[World_Daylight_Environment]
Add Socket: [OctaneGroupTitle]Trace sets, Node[Texture environment], NodeTree[World_Texture_Environment]
Add Socket: Trace sets, Node[Texture environment], NodeTree[World_Texture_Environment]
Add Socket: Shadows exclude, Node[Texture environment], NodeTree[World_Texture_Environment]
Add Socket: Shadows reinclude, Node[Texture environment], NodeTree[World_Texture_Environment]
Add Socket: Toon diffuse ramp, Node[Toon material], NodeTree[Edges]
Add Socket: Toon specular ramp, Node[Toon material], NodeTree[Edges]
Add Socket: [OctaneGroupTitle]Geometry Properties, Node[Toon material], NodeTree[Edges]
Add Socket: Anisotropy, Node[Universal material], NodeTree[Material]
Add Socket: Dielectric IOR, Node[Universal material], NodeTree[Material]
Add Socket: Coating IOR, Node[Universal material], NodeTree[Material]
Add Socket: Film IOR, Node[Universal material], NodeTree[Material]
Add Socket: Sheen BRDF model, Node[Universal material], NodeTree[Material]
Add Socket: Lock render AOVs, Node[Output AOV group], NodeTree[Octane Compositor]
Add Socket: Effects, Node[Render AOV], NodeTree[Octane Compositor]
Add Socket: LOD selection bias, Node[Direct lighting kernel], NodeTree[Octane Kernel]
Add Socket: Neural radiance cache, Node[Direct lighting kernel], NodeTree[Octane Kernel]
Add Socket: Light sampler, Node[Direct lighting kernel], NodeTree[Octane Kernel]
Octane Ocio Management Update Start
Octane Ocio Management Update End. Time cost: 0.00 secs
192.168.50.102
Client connecting to localhost:50051
}

If you need anything from me, ask

Thank you Lino

OK , After many tests and continue crashing I installed Blender 5.0 and just octane, no custom template.
I just tried to switch on valila blender templates that come with the program like 2Danimation,general,vfx,sculpting,storyboarding etc, when i tried to switch again to octane any of the templates you provided on new menu, crashed!

Also I found out that if i ignore your templates , my custom startups working fine and switching between all blender factory templates loading and unloading even add ons.

So I think you should try, it has to do with the templates (Octanerender startup and compositor and denoiser startup)
definitely a bug!

Best,

KONSTANTINOS

dinosgr wrote: Sat Jan 10, 2026 5:23 pm OK , After many tests and continue crashing I installed Blender 5.0 and just octane, no custom template.
I just tried to switch on valila blender templates that come with the program like 2Danimation,general,vfx,sculpting,storyboarding etc, when i tried to switch again to octane any of the templates you provided on new menu, crashed!

Also I found out that if i ignore your templates , my custom startups working fine and switching between all blender factory templates loading and unloading even add ons.

So I think you should try, it has to do with the templates (Octanerender startup and compositor and denoiser startup)
definitely a bug!

Best,

KONSTANTINOS

It looks like the crash only happens if we switch to an octane preset starting from Storyboarding, VFX and Video Editing (starting from General, 2D Animation or Sculpting is fine - no crash), so it must be something related to those templates.
I'll investigate.

Lino the main diference is that octane add-on is not active when you switch to those templates, the same as I do with my custom templates..
Hope this helps

PS
I hope we can still load and unload add-ons using different templates, those predefind blender templates work like It's supposed to work.
The other predefind blender templates has Octane add-on already reside in memory.... and not crashing
but if you want to use eevee you dont need cycles or octane addon to load to free resources, and visa versa.
What i feel is that your template missing a preferences file to first load octane when you switch.

Thank you

What do you mean by "your template missing a preferences file to first load octane when you switch"?