Hi everybody.
I have a question. Everytime a want to put in some new songs I synchronize the 2016 folder where the new files are in.
But I see Mairlist is taking all files as new. So I have to select the new files manually.
I tought Mairlist could recognize the file sthat are allready in the database.
Please post a screenshot of your storage configuration (list of storages), and also of the properties of storage “2016”.
Hope is the correct one 
Ok, the problem is that you have both Z:\ and its subfolder Z:\2006 (and more of them) registered as a storage. You must not do that. Use either only Z:\ (to have everything in a single logical storage), or all the separate subfolders, but not both at the same time.
Also if I only sync Z:\2016? So it’s better to remove Z:?
So I removed Z:\ and now I have many errors 
I think I get it. Z:\ was my networkdisk with all my music in folders.
I added al my music first with Z:\ and afterwards I made folders in mairlist and dragged the files I wanted in these folders.
So the best thing I can do is make the same folders as on my networkdisk en make storages with the same name.
I can’t remove Z:\ mAirlist keep saying it’s in use, even when nothing is playing. Do I have to remove the whole database and start all over?
In the Library, navigate to Storages -> (your Z:\ storage), and check if any items are still displayed in the list.
Yes. See attachment.
No, I mean here:
Yes, but I tried to drag them to another folder but it doesn’t work.
Almost 27000 items in it… Maybe keep the Z:\ storage and discard the individual ones instead?
I think I’ll start all over again, because I want seperate folders for A Currents, B Currents, 90’s, 80’s etc…
This is not the way to do it. I did it as follows:
Make a virtual networkdrive (in my case). I named it E.
Then, I made a folder: ‘Sound_Unit’. In ‘Sound_Unit’, I made separate folders such as ‘Hot Rotation A’, ‘Hot Rotation B’, ‘Slow Rotation’ and such. Also I made folders for the syndicated radioshows and imaging. I only see the files that are not in the database yet at the synchronise window, just as you wished. 
I strongly advise that you do not use any (file system) folders that could lead to a situation where you will move files from one folder to another later, e.g. when moving files between rotations.
mAirListDB keeps a list of all files on your hard drive, and when you move a file around, mAirList will think that it has been deleted, and a new file has appeared in the new location instead. There is a function to fix this in the Sync dialog, but the best thing is to avoid this situation altogether.
Instead, create file system folders based on properties that will never change, e.g. the artist name, or the genre.
Then use mAirListDB virtual folders for the actual rotations.