Hi API Platform Admin Team,

I was previously using API Platform v3.3.7 for my backend and API Platform Admin v3.4.7 for my frontend.
After upgrading to API Platform v4.0.2 and API Platform Admin v4.0.1, I encountered the following error on the frontend :

Cannot fetch API documentation:
The API documentation has no "http://www.w3.org/ns/hydra/core#supportedClass" key or its value is not an array.
Have you verified that CORS is correctly configured in your API ?

The hydra-prefixed tags have been removed from my APIs as expected, but the API responses are otherwise in the correct format.

Interestingly, if I revert the backend to API Platform v3.3.7 while keeping the frontend at API Platform Admin v4.0.1, everything works fine. The issue only appears when both the backend and frontend are on the latest versions (v4.x).

Thank you for your help!