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Hi Octane development team,

I have encountered two serious issues with OctaneRender 2026.6 / C4D Plugin 2.0.3 in Cinema 4D 2027.

Both issues do not occur in Cinema 4D 2025 using the same Octane plugin version.

Issue 1: Crash when rendering large Alembic (ABC) geometry

When rendering a scene containing large Alembic (ABC) geometry in Cinema 4D 2027, Cinema 4D crashes.

The scene contains no assigned materials or camera objects, and motion blur is disabled.

Test results:

C4D 2025 + Octane 2.0.3: Works correctly.

C4D 2027 + Standard Renderer: Works correctly.

C4D 2027 + Octane 2.0.3: Crashes.

I also checked the Cinema 4D crash report.

The exception is ACCESS_VIOLATION (0xC0000005) in c4d_base.xdl64.

The crashing thread contains the following call stack:

c4d_base.xdl64
c4d_base.xdl64
io_alembic.xdl64
io_alembic.xdl64
io_alembic.xdl64
io_alembic.xdl64
c4d_base.xdl64

This suggests a possible compatibility issue involving Octane's geometry extraction process and Cinema 4D 2027's Alembic evaluation.

Issue 2: Cinema 4D becomes unresponsive when scrubbing the timeline with Live Viewer active

When Octane Live Viewer is actively rendering in Cinema 4D 2027, dragging the timeline playhead causes Cinema 4D to freeze and become unresponsive.

The same operation works normally in Cinema 4D 2025 using Octane 2.0.3.

Steps to reproduce:

1. Open an animated scene in Cinema 4D 2027.
2. Open Octane Live Viewer and start interactive rendering.
3. Drag the timeline playhead to change the current frame.
4. Cinema 4D becomes unresponsive.

Expected behavior:

Cinema 4D should remain responsive while the Live Viewer updates the rendered scene as the timeline changes.

Actual behavior:

Cinema 4D freezes and stops responding.

I am not sure whether these two issues share the same underlying cause, but both appear to be related to the C4D 2027 integration.

System information:

Cinema 4D 2027.000
OctaneRender 2026.6 / C4D Plugin 2.0.3
Windows 10, Build 19045
Intel Core i7-13700KF
NVIDIA GeForce RTX 5070 Ti
NVIDIA Driver 580.97

Attachments:

1. Cinema 4D project file and the required Alembic cache.
2. Cinema 4D crash report (_BugReport.txt).

I have attached the project and crash report to help reproduce and investigate the issues.

Could you please investigate these problems?

Thank you for your help.

Hi,

Thanks for the report and the scene, they made it easy to reproduce.

Good news: it isn't Octane. The crash is a Cinema 4D 2027 bug in its Alembic module. Your ABC changes topology between frame 0 and frame 1, and C4D 2027 crashes when it evaluates across that change. The same scenes render fine in C4D 2025.3.3 and 2026.4 with the same Octane plugin.

To see it yourself, open the attached copy of your scene (abc-bug_noOctane.c4d, with all Octane data removed), put it next to abc1.abc and render frames 0–5 with the Standard Renderer. It crashes there too. The timeline freeze is very likely the same issue.

Until Maxon fixes it, you can work around it by starting your render from frame 2, or by re-exporting the ABC with constant topology.

ciao,
Beppe