Update :- Talked to a Googler working with Google Play console team regarding this issue. One misconception I had at the time was that you need to retain an APK if you want to have a staged rollout. I discussed this with him, and he clarified that it is not needed. Even in staged rollout, with no retained APK, Google play will show an install option to users who visit the app's page. Hope this clears doubts for someone facing similar issues.
I was having the same problem and I fixed without clicking "Retain" for previous version and uploaded a new one and then "Start Rolling" button turn into clickable and done!! ^_^
This is what has worked for us for now, hopefully there will be a better solution known to someone, this feels like a hack rather than a solution.
which channel? Production / beta / alpha ?
I see this is the accepted answer, but i don't understand what you actually did to make it work. What does it mean to not click 'Retain' for previous version? Where are you seeing this 'Retain' option? I go to my app release, browse for an apk, upload it then review and i see the error. I don't get a retain or do not retain option anywhere.
@ Dallas Caley I also having same problem how you solved..please help me sir
@DallasCaley @GowthamanM Sorry to not reply earlier, I didn't get notification for some reason. When you start a new release, 'Prepare release' section, you have a section called
APKs to retain
, you can see the retained APK there.