Upgrade HDP via Ambari

I'm upgrading my cluster from HDP2.4 to HDP2.5

Following the instructions, I already performed the ambari-server and ambari-agent upgrades. I wanna now upgrade HDP thanks to "Manager Versions > Register version" action in Ambari admin interface.

The problem is that i'm not able to "Save" (the button "Save" is disabled - see orange circle in image below) even once I've provided the tight Base URL for my OS (redhat 7). I don't know why ...

Solution

Solution found after inspecting the AngularJS code of the button : I had to give a version number in the top right text input.