How can I delete Mainfolder in Lightroom folders

[RobVink]

How can I delete Mainfolder in Lightroom folders

[dj_paige]

Is this a Lightroom Classic question?

What is "Mainfolder"?

[RobVink]

Yes this is about Classic, 

 

I mean this with main folder.

A friend of mine has one double and one doesn't exist, but I can't found a way to remove it. only removing subfolders

[Rob_Cullen]

Your screen-clip ( if it is yours) shows a Drive that is offline, that may contain many photos referenced in the Catalog. Deleting this could remove many photos from your Catalog.

A friend of mine has one double and one doesn't exist,

In this case, where the same Drive appears twice, there is a specific procedure that must be followed to correct the problem. See these links for details-

DUPLICATE DRIVE displays same hard drive twice