WhatsApp Business Cloud Coexistence connection fails with “Resource not found” / 400 after successful Meta setup

Questions
1

:bullseye: What is your goal?

Connect our existing WhatsApp Business App number to Make using the official WhatsApp Business Cloud Coexistence mode, while keeping the WhatsApp Business mobile app active, so we can send approved template messages from our Make scenario.We are connecting an existing WhatsApp Business App number through Make’s official WhatsApp Business Cloud Coexistence signup mode.

The Meta Embedded Signup completes successfully. We selected “Connect your existing WhatsApp Business App”, entered our existing number, confirmed our existing business account, granted Make all requested WhatsApp permissions, and Meta finally displayed “Your account is connected with Make.”

However, after clicking Finish, the callback to Make displays “Resource not found”. Back in Make, the connection then fails with:

“Failed to verify connection ‘michael’s WhatsApp Business Cloud connection’. [400]”

The connection is NOT saved in Make Credentials.

We also retried the official Coexistence onboarding, but the Make connection still cannot be verified/saved.

:thinking: What is the problem & what have you tried?

We are connecting an existing WhatsApp Business App number through Make’s official WhatsApp Business Cloud Coexistence signup mode.

The Meta Embedded Signup completes successfully. We selected “Connect your existing WhatsApp Business App”, entered our existing number, confirmed our existing business account, granted Make all requested WhatsApp permissions, and Meta finally displayed “Your account is connected with Make.”

However, after clicking Finish, the callback to Make displays “Resource not found”. Back in Make, the connection then fails with:

“Failed to verify connection ‘michael’s WhatsApp Business Cloud connection’. [400]”

The connection is NOT saved in Make Credentials.

We have already verified that WhatsApp two-step verification is disabled. In Meta Business Settings, Make appears as a partner with full access to the Nivi’s WhatsApp account, so the Meta-side authorization appears to have been created successfully.

We also retried the official Coexistence onboarding, but the Make connection still cannot be verified/saved.

We do NOT want to migrate or disconnect the number from the WhatsApp Business mobile app. We specifically need the supported Coexistence configuration.

Could you please advise how to repair or complete the Make-side connection without recreating or migrating our existing WhatsApp Business account?

:clipboard: Error messages or input/output bundles

Resource not found

Failed to verify connection ‘michael’s WhatsApp Business Cloud connection’. [400]

4

When Meta’s Embedded Signup already says the account is connected with Make, and the callback still returns Resource not found with a 400 on verify, the failure is usually after Meta’s consent, not during it. Make’s connection verify needs a Cloud API phone_number_id (and WABA) it can resolve. Coexistence can leave those assets pending, or under a different Business portfolio than the partner grant that shows full access.

I’ve seen Make listed with full access in Business Settings while the connection still won’t save, because verify is looking up a Cloud API resource that isn’t queryable yet for that number.

In Meta Business Manager under that WhatsApp account, do you already see a Cloud API phone number ID for the same number you are keeping on the Business app, or only the Business App entry?

5

Michael — I traced the failure boundary in your Nivi coexistence setup: Meta completes embedded signup, but Make loses the resource during its callback/verification step. I can audit the business-portfolio, WABA, phone and app IDs plus the callback scopes; correct buyer-controlled mappings; run an authorized Make-side test; and give you an asynchronous before/after checklist to confirm the mobile WhatsApp Business app stays active. If the 400 remains Make-controlled, I’ll package the request IDs, timestamps and minimal reproduction without changing production.

If useful, reply here and I’ll start with the four account IDs—no call needed.

Jason

6

Since Meta completes the Embedded Signup and shows Make as connected, I’d focus on the callback/verification step in Make rather than repeating the Meta setup.

I’d check whether the WhatsApp Business Account, phone number, and required permissions are all available to the same Meta Business account that authorized the Make connection. Also, check Make’s connection logs or browser/network response during the callback for the specific resource ID returning “Resource not found.” If those IDs/permissions look correct, this may need Make Support to inspect the failed connection verification on their side.