A component that is not sub process start cannot have any link OnComponentOk / OnComponentError in input

VictorFaure — Thu, 20 Mar 2025 10:53:04 GMT

Hello,
I'm currently working with a job that either calls to a DB using tDBInput with JDBC connection OR requesting an API.

The output schema is not known so it is one column that is of type Dynamic.

My goal is to unite (somehow) the output from DB and API to write to a file later, with tUnite component I get the title message : "A component that is not sub process start cannot have any link OnComponentOk / OnComponentError in input".

My question is either how to tackle the current issue, or how to join both output that should never output at the same time, meaning either the DB will output something or the API.

Respectfully,

Victor Faure

Re: A component that is not sub process start cannot have any link OnComponentOk / OnComponentError in input

gouravdubey5 — Sun, 01 Feb 2026 20:21:59 GMT

Hello,

Yes, the image has been reviewed.

Based on the job design shown, the error is expected and is caused by a control trigger being connected to a component that is not a valid subjob start.

In Talend, only specific components can start a subjob. Components that are part of an active row flow (such as mapping or transformation components) cannot receive or initiate control links like OnSubjobOk or OnComponentOk.

In the provided design, a trigger is attached to a component that is already inside an existing subjob, which leads to the validation error: A component that is not sub-process start cannot have any link

Recommended actions:

Ensure that control triggers originate only from valid subjob start or end components.

Restructure the job so that each triggered flow starts from a proper start component.

Use row links instead of control links when the logic is data-driven.

This is a design-time validation issue and can be resolved by correcting the job’s control-flow structure.

Thanks,

Gourav

topic Re: A component that is not sub process start cannot have any link OnComponentOk / OnComponentError in input in Talend Studio

A component that is not sub process start cannot have any link OnComponentOk / OnComponentError in input

Re: A component that is not sub process start cannot have any link OnComponentOk / OnComponentError in input