Any electricians on here?

[zinedine]

Pretty much this, old ceiling rose and the new light just needed live/neural. At the ceiling rose the cables weren't labelled and the neutral wasn't marked as switched live, but it was at the switch itself.

I've fitted a new switch (old one was a dimmer) and it's now working...for now!

If the old rose had a wire for a pendant hanging from it your new light just goes to the two connections the pendants wires were connected to.
You should have marked all the wires or took a photo but a bit late now. If you've got a multi meter you should be able to find out what is what. Put some red or brown tape around the switched live at the rose and the switch. Make it easier for future changes.

 

[fireballs]

If the old rose had a wire for a pendant hanging from it your new light just goes to the two connections the pendants wires were connected to.
You should have marked all the wires or took a photo but a bit late now. If you've got a multi meter you should be able to find out what is what. Put some red or brown tape around the switched live at the rose and the switch. Make it easier for future changes.

Aye, schoolboy error not capturing what was there in the first place. The old pendant was connected with it's own wires but I took down everything including the old rose and fixing bracket ready for the new light so I've had to use wago connectors and add an extra length of cable.
It was less complicated than it could have been as it must be the last on the loop, so no loop out just in and switch.

 

[zinedine]

Aye, schoolboy error not capturing what was there in the first place. The old pendant was connected with it's own wires but I took down everything including the old rose and fixing bracket ready for the new light so I've had to use wago connectors and add an extra length of cable.
It was less complicated than it could have been as it must be the last on the loop, so no loop out just in and switch.

I was going to suggest use wago type connectors instead of a junction box or strip terminal. Put them in a wago box though don't just shove them up into the ceiling void.