Dino - I believe that this error will NOT show for materials. So it will only pop if you have make an invalid connect to a Kernel, Camera or Environment pin/property, which should make it easy to track down. In the case with the scene you posted, it was the node connected to the Environment Power. To resolve this, plug the "A is equal to B" node into an Octane Float Value X, which can then be plugged into the Environment Power.Also - looking at the "Error connecting cmLogic : Non-Octane nodes can only be plugged into Octane Float, Int and Bool nodes" issue...I cannot get the plugin to allow these connections to force this message in order to assess the issue further. Do you have a scene that pops this message so I can use it as a test scene?
Paul