Predictive Outbound 500 on Campaign Start via Platform API

Genesys Cloud Routing
1

Struggling to figure out why the Platform API returns a 500 Internal Server Error when attempting to start a predictive campaign via POST /api/v2/outbound/campaigns/{campaignId}/start. The application is a Premium AppFoundry integration handling multi-tenant operations. The campaign configuration appears valid in the UI, and manual start works without issue. However, automated triggers fail consistently.

  1. The OAuth token is generated using client credentials with outbound:campaign:write scope.
  2. A new campaign is created via POST /api/v2/outbound/campaigns with standard predictive settings.
  3. The API returns 201 Created successfully.
  4. Immediately invoking the start endpoint yields 500.
  5. Response body contains: {"message":"Internal Server Error","code":"INTERNAL_ERROR","details":"Campaign status transition failed due to worker pool unavailability"}

This occurs across three different tenant organizations. The issue persists even after waiting 30 seconds post-creation. Is there a specific delay required between creation and start for predictive campaigns? Or is this related to how the AppFoundry environment interacts with the outbound worker pools? The documentation does not specify a mandatory wait time for this workflow.