@dspreadbury Thanks for your comment. It’s always good to hear from a developer. I am trying out Sibelius Ultimate with a build that was released earlier this year. It’s interesting that you still have insights into your competitor’s product, even some years removed!
In general, might it not be helpful for Dorico to give some warning to the user rather than disabling it? For example, it’s common to turn notes red if they’re out of range. Why not turn the repeat bar red if Dorico cannot repeat? An automatic disabling makes it appear as if Dorico is just broken. In this instance, Dorico should not have had any problem with the first repeat, and failing to repeat from the end would have given me feedback that Dorico is looking for some other notation.