There have been a couple of reports since the release of Dorico 1.1 of being unable to reopen projects that have previously been saved.
We believe we now know what causes this problem, and are working on a fix for the forthcoming minor update, but in the meantime we want to provide some advice on how to avoid this problem.
When opening an existing Dorico project, you receive the error Error opening file, and the project cannot be opened.
This problem is caused by using either Write > Split Flow or right-clicking on a flow in Setup mode and choosing Duplicate Flow from the context menu when the project contains an Empty-handed Player, i.e. a player not holding an instrument.
Before you use Split Flow or Duplicate Flow, either delete the Empty-handed Player or assign an instrument to that player.
We are sorry for the inconvenience caused by this bug, and hope that the above information will help users to avoid running into it before a proper fix is available.