The following happened and is happening on both my tablet and phone:
I synced and uninstalled the previous version.
I installed Beta 15 using the apk.
When I opened 1Password, I was presented with a screen saying that there was a new version that had to be installed. I could not get past that screen, so finally I did the automatic install.
I logged into 1Password and it said login accepted, then went immediately back to the login screen.
I logged in again and my items appeared behind a pop-up - "Sync error... Please report this error so that we may assist you."
This now happens every time I log in.