Lines can only be applied to Voice 1 note positions (bug?)
When you try to apply a line (using, for example, the hooked text-line marked "VII" from advance palette > lines) MuseScore uses Voice 1 to establish the anchor points at which you can place the beginning of the line.
This means that if, for example, Voice 1 only shows quarter notes you are unable to anchor the line at an intermediate eigth-note position occupied by a note in Voice 2 etc. You have to offset it or adjust one of the handles.
Surely this can't be right?
Comments
Do you mean, when initially dragging the line to the score? What I find is the dotted line won't be drawn when adding between voice 1 notes, but the line adds just fine. Also, I can add to a voice 1 note then move the anchor point normally (double click, select left handle, shift+left/right) and it works fine, dotted line and all.
The fact that the line doens't draw when initially dragging is worth reporting officially.