I have made the decision: Drupal Commerce does not yet work for me. After months of patience with phrases like "straight out of the box" and demonstrations on equipment different from what a shopkeeper would use, I am going back to Ubercart. Drupal 7 is so big that it needs a database upload rather than a one-click install from a server gizmo. So I install Aquia Drupal stack installer and the first thing it does, even before properly installed, is come-up with a puzzling error message. Vaguely familiar. This is where a diary helps.