'Start rollout to beta' disabled in Play Store Developer Console

I am ready to send my first app to beta testers, so i click on 'Manage Beta' > 'Manage testers'

.

and 'Save' and 'Resume'

APK is uploaded > 'Review'

The review summary says 'This release is ready to be rolled out.', but the button labled with 'Start to rollout to beta' is disabled: .

Solution 1:

To see what still needs to be done, you can hover your mouse over the grayed out checkmark. There will be a popup that tells you what you still need to finish.

Solution 2:

Saranga is right from my experience. Before I could send out a beta version I had to ensure I had the images under store listing included. Just look at the side bar (see image) and see whats greyed out and thats where the problem was for me.