Hello everyone,
I’ve had Cubase for nearly half a year now and recently I’ve noticed these white lines on some tracks and I don’t know what they mean. I’ve read through the whole Operation manual but if it’s written in it, it must have been somewhere where I was reading at a time when I didn’t know about them and it must have slipped through my fingers. I tried to google it, but I’m probably using wrong keywords. So my humble question to you good people is - what are these white lines next to the number of track in the project window and above the name of the track in the mixconsole? See the picture - red oval is with the line, orange is without. And it looks like it only sits on my audio tracks. Thank you for your help. 
Its to do with whatever midi controller you’re using.
If you remove any external controllers you’re using from device setup they’ll go away.
I’m using a Nektar Panorama P6 keyboard which has 8 faders, the lines indicate which tracks the controller is relating to.
Hi,
These lines are useful when you use any hw controller like Mackie Control. The the lines inform you, what bank is selected, so what tracks are currently assigned to the hw and you can control them from the hw.
If you don’t u send any hw controller, disable them in the Devices > Device Setup > Remote Devices.
Interesting… Thank you for your replies gentlemen.