I have two Dolibarr v7 installed in my local one is modified(have few custom modules and code modification) and another one is fresh Dolibarr v7 the fresh one’s API Explorer is working fine but the modified not. I am looking into into it and trying to find the issue but not sure how and where to check
Sorry @priojk not possible to upgrade at this moment as we have modified in some core areas too. But will try in future for sure.