# Component is blocking downstream flow even though it is on an inactive branch **URL:** \ **Category:** KNIME Analytics Platform\ **Tags:** bug\ **Created:** [February 20, 2023, 3:20pm UTC](https://forum.knime.com/t/component-is-blocking-downstream-flow-even-though-it-is-on-an-inactive-branch/62141 "2023-02-20T15:20:44Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![takbb](https://forum-cdn.knime.com/user_avatar/forum.knime.com/takbb/32/57077_2.png) [@takbb](https://forum.knime.com/u/takbb)\ **Post date:** [February 20, 2023, 3:20pm UTC](https://forum.knime.com/t/component-is-blocking-downstream-flow-even-though-it-is-on-an-inactive-branch/62141/1 "2023-02-20T15:20:44Z")
(KNIME AP 4.7.1, Windows 10) As the topic name suggests, I am having a problem where a component on the inactive branch of an Empty Table Switch is blocking the flow. This should not occur. I see that something similar to this has been reported before eg > [@Issues related to node/component execution within inactive branches](https://forum.knime.com/t/issues-related-to-node-component-execution-within-inactive-branches/45317): > > Last week I opened up a support case related to calling sub-workflows and not being able to see the widgets on the KNIME WebPortal. This has been answered by @Alice_Krebs. As a workaround we’ve implemented the use of many many case switches to achieve the required results, but unfortunately we came across a big issue, which is the unwanted execution of nodes/components inside components of inactive branches. In the attachment you will find a test workflow which shows the issue: [Inactive Branc…](https://forum.knime.com/uploads/short-url/lODXDJMWOYiLikxSzSTfdZRTNjD.knar) In that thread, it suggested that a bug fix would be implemented in release 4.7. I have just stumbled on something that looks very similar to this in 4.7.1 whereby a component is not fully deactivated in an inactive branch and causes it to block. Note that it does _not_ happen with all components. Given that the above issue has already been identified, I wanted to check if this is the same issue (ie still awaiting a fix) before creating a minimal workflow to demonstrate the problem, which I can do but will take time. In this case, I believe the issue is possibly to do with the use of flow variables that are created within the component and used in the configuration of the Component Output node. Under some circumstances (to be determined) the component will error as the variable is undefined. (It is undefined because the nodes within the component that that would have created it are inactive!). This causes the component to error on the component output node and block the downstream flow, even though the component is on the inactive branch and should not be executing. ---
**Author:** ![ArjenEX](https://forum-cdn.knime.com/letter_avatar_proxy/v4/letter/a/97f17d/32.png) [@ArjenEX](https://forum.knime.com/u/ArjenEX)\ **Post date:** [February 20, 2023, 4:26pm UTC](https://forum.knime.com/t/component-is-blocking-downstream-flow-even-though-it-is-on-an-inactive-branch/62141/2 "2023-02-20T16:26:51Z")
The fix for that reported issue in V4.7 under AP-19271 was specifically for the CASE Switch branch according to the patch notes, so I’d guess they did not include the Empty Table Switch node in that fix and you’re looking at a similar but new issue 😉 ---
**Author:** ![system](https://forum-cdn.knime.com/uploads/default/original/1X/ab3ccf34482a0329361734a18199390177204f15.png) [@system](https://forum.knime.com/u/system)\ **Post date:** [May 21, 2023, 4:27pm UTC](https://forum.knime.com/t/component-is-blocking-downstream-flow-even-though-it-is-on-an-inactive-branch/62141/3 "2023-05-21T16:27:05Z")
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