Hello @WillemD,
Thanks for bringing this to the Community!
The issue you’re running seems tied to a temporary security restriction HubSpot put in place following a recent security incident. Developer accounts created after March 11th, 2026 are currently unable to create or fully configure public apps. The team expects to lift this restriction within the next day or two. You can track updates here: HubSpot Trust Center | Powered by Conveyor
Thanks for your patience on this!
Sam, Community Manager