some ideas:
- you should make sure to have Rserve 1.8.6 - it does not show up on your configuration so the installation might not have been successful
- I do not see the Cairo package which is also needed
- you should check if KNIME does point to the right installation of R and not another version you might have on your machine
At the bottom of this hub workflow, there are links to relevant articles. You might get some ideas there
Then you could toy around with advanced settings although I doubt that that would help - you might try nonetheless
