Can you give more context and explanation? What’s the prevailing time signature?
Do you really want to move a barline? If so, which one? Or do you want to break a 4/4 bar, with one beat on the next system?
The easiest way is to create a System Break on the next bar, and then in Write mode, move it back using Alt-Left.
Its not good to start multiple topics on the same issue. Just confuses people and it’s not quite according to the guidelines/
What do you want t move? All I see is what looks like whiteout.
I think it’s about the incomplete bars crossing staves. Ben answered this perfectly.
Isn’t there a Preference that must be set so that system breaks can happen anywhere in the bar, in order for this to work?
With that preference set correctly, you can put the system break directly on that fourth beat (Engrave mode, shift-S)