"Starting the Octane API twice is not allowed"
Posted: Thu Aug 27, 2026 5:29 pm
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
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?
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!Any help?