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Question

Action block with a credentials link crashes the automation builder on selection

  • August 11, 2026
  • 0 replies
  • 68 views

Hi,

 

An Automation block (`AppFeatureBlock`, kind "action") on the workflows infrastructure crashes your

own frontend the instant it's selected as an action, before any manual configuration happens.

 

Error (browser console):

```

Iae: fieldType not found

at zae.Nae (MF-mf-lite-builder.BlhKIoZd.min.js:52:191380)

...

onBlockSelect → setWorkflowVariable → updateWorkflow → setQueryData → setData → Nae

```

The trace shows it fires while the builder auto-initializes workflow variables for the block's

fields right after `onBlockSelect`.

 

Isolated to one specific cause via a controlled test: on a throwaway second app, a trivial

action block (one primitive string field, nothing else) selects and configures without issue.

Adding *only* a `credentialsConfig` link to an `AppFeatureCredentials` feature — no other change —

makes the same block crash with the same error at the same point. I also checked whether the

credentials feature having zero stored credentials mattered: tested both an empty list and a real,

successfully-validated stored credential (via our own `/monday/authorize` flow) — both crash

identically. So it's specifically the presence of `credentialsConfig` on the block, independent of

whether anything is stored.

 

Reproduced on two independent apps (11849695, our real app; and a second, minimal app created only

to isolate this), with fields created both via the UI and via `manifest:import`, with several

different field-type combinations. Every action block with a credentials link crashes on selection;

every one without a credentials link works.

 

One thing I can't explain, and would like your help with: earlier this week, an automation using

this same app's block — which already had a credentials link — did save and run successfully once.

Between then and now we rebuilt the block several times (new internal key, new field schema), so it's

not the literal same feature object anymore, and I can't tell from the outside whether that matters.

Is there something about how a credentials-linked block gets registered that would make a freshly

recreated one behave differently from one that's existed for longer? Or is this a known issue in the

lite builder bundle's handling of `credentialsConfig` that you're already tracking?

 

Confirmed on a second, separate, paid monday account — rules out plan/account-tier as the cause.

I installed the same app into a different, paid monday instance (distinct from the free developer

account used above) and tested there:

- Workflow Builder (the new, beta builder): your own native actions select and configure fine — so

it works correctly on this account. Our block does not appear there — but per your own docs

(support article "New Automation Builder"), that's expected right now: "Automations from third

party marketplace apps won't appear in the action list when creating a new automation using the

new builder. To use these apps, you'll need to continue creating automations directly from the

app's templates." I'm not reporting that part — it's documented, known beta behavior.

- Classic automation flow (where third-party blocks *are* offered): same crash as on the developer

account, at the same point, both building from scratch and from an app template.

 

So the crash isn't specific to a free/developer-tier account. It reproduces identically across two

unrelated monday accounts, in the one surface (classic/"lite builder" automation flow) where

third-party blocks are actually supported today.

 

App id: 11849695. Live version has the crashing block at slug `invoice_draft_v2`.

 

Thanks!