missing black line of the timeline

Hi,

The black line of the timeline which allows you to better position your rushes, not to overflow on another, to set a sound right at the time of the shot etc

Do you know which one I mean? Presented as the basic blue cursor.

Well, it's gone, and I don't know how to put it back, unless it's a bug. I'm in the process of building a trailer and having to position everything to the nearest millimeter is taking up a lot of my time...

Thanks in advance