In the Scripting -> R predictor node the workspace variables are called “knime.flow.in”, “knime.in” and “knime.nodel”. The last one should probably be “knime.model” as shown in the sample R Script line, when the node is being placed. The sample code can’t be used at the moment “knime.out <- cbind(knime.in, predict(knime.model, knime.in))”.
The R Predictor takes the workspace objects from the preceding R Learner node. Can you please check the name of the model you create in that node?
Just using the default values in both R Learner and R predictor, it’s knime.model for me in KNIME AP 3.7.1, so maybe there’s a typo in your Learner config?