Dear @ipazin ,
I can confirm @joshuahoran 's experience. When I was a Knime newbie, whenever I had a particular arrangement of nodes and metanodes, I could no longer right-click and execute downstream nodes, which was somewhat frustrating. This happened quite often. Of course, I could always select “execute all”, but that is not always an option when the workflow gets large or processes large amounts of data.
It might not be a problem when the workflow is “deployed”, but in my case development is all I do because I mostly use Knime in the same way other people use Jupyter or RStudio notebooks: a convenient data processing and analysis workbench. I can’t be the only one who uses Knime in this way.
The problem may also arise with other nodes than the R/Python nodes that I mention in my first post. One of the endpoints in my “main” daily workflow produces a volcano plot. Suppose a student of mine tries to use the workflow on his data to produce a volcano plot. He enters the data in the beginning of the workflow and tries to produce to produce the volcano plot by right-clicking on the volcano plot metanode. Bummer: he cannot right-click and execute that metanode. Student is confused and disappointed and does not understand why his supervisor is so excited about Knime. He throws the towel and returns to the Excel sheets he know best. We don’t want that to happen, right?
However, it turns out that the node that is just two metanodes upstream from the volcano plot node CAN be executed by right-clicking it. The are no R or Python nodes in those metanodes. I will try to isolate this specific occurrence and make another example workflow, if that helps.