A parent workflow with two sequential Run Workflow calls causes the second one—“Run URLs” in “Query”—to fail, even though each works fine alone.

Community Discussion
1

Two sequential “Run Workflow” calls: second one (“Run URLs” in “Query” workflow) fails

Context: Parent workflow has two Run Workflow blocks set to sequential (lower test cost, as I stop the run). Each sub-workflow works alone. With both present, the second call—“Run URLs” inside “Query”, doesn’t execute/return outputs.

Remix:

https://app.mindstudio.ai/agents/open-prolearn-ai-studio-v2-bd0ca4e1/remix

Repro (short):

  1. Parent calls Sub A → Sub B (both via Run Workflow, sequential)

  2. Whichever is second fails or returns empty (even if you include any other Run Workflow block, such as an empty one, it will not run).

Already tried:

  • Unique input/output mappings (no collisions)

  • Launch Vars + Terminator JSON set in both subs

  • No circular calls; no parallel groups

  • Debugger shows no clear error for the second call

Ask:
Is there a known issue or hidden constraint with two sequential Run Workflow calls?

Please help! I’m stuck for the past days…

2

Hi @fernando.damasio,

Yes, it looks like you have been encountering a bug. The system has protections in place to detect and prevent infinite loops (e.g., if Main.flow has a run block that spawns Sub.flow, and Sub.flow has another block in it that spawns Main.flow…), and it looks like the pattern you have in your agent (Main → Child → A, then B) was incorrectly triggering those protections and causing the execution to error. The bug has been fixed and your agent should run as expected if you give it another try. Thanks for reporting this!

Sean

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Thanks very much for your quick and assertive reply @sean !