I tried to submit my updated application to playstore. When I tried upload the apk on production, there was notice saying
Play Store will require that new apps and app updates target a recent Android API level. This will be required for new apps in August 2018, and for updates to existing apps in November 2018. This is to ensure apps are built on the latest APIs optimized for security and performance.
Currently, my application was set minSDKVersion 19 and targetSDKVersion as 23.
Does that mean I have to update my application to targetSDKVersion 26?
I have tried to change this and upload it. I seems to have error saying about the downgrade (Sorry I should have make a note of the message).
Does that mean I have to update my application to targetSDKVersion 26?
Yes. But for now its just a warning, it will enforced from beginning of August for new apps. Do take note that deadline for app update is November.
have tried to change this and upload it. I seems to have error saying about the downgrade
Since you don't have complete error message, one probable cause of this issue is, you are trying to upload an app which has VersionCode less than the app available on play store. Re-check your version code and increase it if needed.