"Starting the Octane API twice is not allowed"

[moritzw]

Hi, it's been a while, thought I revisit a more modern Octane since for my good old v4 license, I always need to go back to my old GTX 1080 Ti, losing all the power of my RTX 3070 Ti
But I don't get it to run in Blender:

Blender 5.2.0 LTS
Octane Render Prime 2026.4 - Octane Blender Addon Server v.31.10.0 (Activated)

Reproducable behavior:
I start Octane Render Prime (or I close Octane Render Prime if it was already open, and freshly re-open it, same result)
I start Blender 5.2.0 LTS
I switch to Render tab and switch render engine to Octane
When I open Octane Log i always get

Code: Select all

Started logging on 27.08.26 19:22:07

OctaneRender Prime 2026.4 (15030000)

module dir = 
device 0
  supports d3d11 SS 1
  adapterid 62126
  used for render   1
  used for tonemap  1
  used for denoise  1
  uses priority     0
Server listening on 0.0.0.0:50051
Starting the Octane API twice is not allowed!

I also installed the plugin for Unreal in parallel, but I rebooted and did not open Epic Games Launcher and still have the same error.

Any help?

[moritzw]

Update: Got it to work for now, by keeping the log window open on the side, clearing the log and observing it to not show the same repeated

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"Starting the Octane API twice is not allowed"

When manually refreshing the Octane Add-On in Blender, it started showing regular Octane Log entries and seems to work for now.

[linograndiotoy]

Hi,

I get the "Starting the Octane API twice is not allowed" message in the log as well, and in my case it does not affect Octane's normal operation.

As far as I understand, it simply means that the Octane API was already initialized and another attempt was made to start it again. The second initialization is therefore ignored.

So I don't think that message itself is necessarily related to the problem you were experiencing, especially since Octane is now working correctly after refreshing the addon.

It would also be interesting to see what is currently shown in the Device Preferences window.