Greetings, I've been using OctaneRender for Unity to render various passes for a given scene.
The thing is, when rendered using the Info Channels kernel (and saving as beauty render pass) or the save button in the PBR viewport, the resulting image consists of 128 bits per pixel, with 4 channels ...

I had the error with ErrorCode: 126 when I updated to OctaneUnity 1.1.1.1341 and when I closed the Unity Project and opened again it disappeared.
Maybe this is your case too.
Best of luck!