WARN Loop End (2 ports) 0:372 Loop start and end nodes are not in the same workflow

I don’t know why im getting this error that causes the workflow to stop

HI @malik,

I would say that somewhere in Metanode you have another node for loop start. Can you check?


Hi @ipazin
I do have different internal loops- but they are match. However, i have an old version that works fine
for me- i just get this error when i tried to merge flow variables
This version works fine

Hi again @ipazin
I have uploaded the workflow to the Knime Hub. See


Please send me your e-mail and then i can send you an input file.
My e-mail is malik.yousef@gmail.com


Hi @malik,

Wow! A big workflow with lot of Metanodes and loops :open_mouth:

I have checked it quickly and in RCE Metanode there is SavesGenasAtEachLevel Metanode that starts in Recursive Loop Start (loop 369) but doesn’t end in Recursive Loop End so I guess it is the one causing problems.

Data is saved within workflow so it is not needed.


1 Like

This is not the cause of the problem- See this figure the SVM-RCE that include those meta-nodes are working fine. The problem when we get back from the meta-node SVM-RCE then it says "
WARN Loop End (2 ports) 0:439 Loop start and end nodes are not in the same workflow

Also hen i click on the loops start or end then “select loop” i see that they are matching.
@Iris what do you think the problem ? And it is also a warning !!

I solved the problem by converting the meta node to component node!


Hi @malik

let me explain a little bit what happened in the back.

If you have a normal metanode, the nodes inside will be treated the same way as if you would have the node expanded to the top most level.
This means that in case there are other loops inside the metanode the order of the loop end must be deterministic. Mostly this is not the case if one loop end is not connected to the second loop end. And this is also the way how to fix this, by connecting the first loop end via flow variables to nodes before the second loop end.

By using a component you change the way how KNIME treats the nodes inside of the component. We will now execute the components inside independently and as one single unit. The component needs to always work independently of the outside.

I hope this helps a little bit understanding the difference between metanodes and components in this setup.

Have a great week!
Best, Iris


This topic was automatically closed 182 days after the last reply. New replies are no longer allowed.