Been doing this without a hitch for 15 years.
In my case, I DJ on a MacBook M1 with Traktor 4.2 installed, and my home studio has a Windows desktop, with Traktor 4.2 installed. My Traktor root folder and all of my music are on the same external SSD (in separate folders of course). So when a gig is over, I take the external and plug it into the desktop and use Traktor at home (mainly to manage collection, work on library, etc.). Here’s how:
When a gig is over, and I intend to use the collection at home on the Windows environment next, I save and close Traktor, and then I edit the collection.nml file, located in Traktor’s root folder within the external SSD, using a text editor (either PSPad on Windows, or BBEdit on Mac). The idea here is to do a mass replacement of the path for each of the music files in your collection. Since Macs use drive NAMES, and Windows uses drive LETTERS (followed by a colon), what you need to do is to a mass-replacement of your drive name with your drive letter (the drive letter your desktop already assigns it in Windows), followed by colon. In BBEdit, open collection.nml, and go to Search, and then choose Find, and input your external disk name under Find, e.g., “My DJ Drive” without the quotes, and input the drive letter (always a capital letter) followed by colon, e.g., “W:” without the quotes, under Replace. Make sure you inputted both correctly (this is case-sensitive), and hit Replace All to execute the change. Save the file and close BBEdit. To go back to Mac from Windows, reverse the operation: replace drive letter & colon with drive name.
You have to do this prior to trying to use the collection in the new envionment (Mac or PC), otherwise collection.nml instructs it Traktor to look for the song files in a path that doesn’t exist, since the paths between Mac & PC are inherently different, and Traktor will be missing ALL of your music files. Sure, you could then do a traditional mass relocation of missing files inside Traktor, but it would take probably hours if you've got 30,000 tracks like myself. Editing the collection.nml as described above changes the expected location of the music files so that the incoming environment (Mac or PC) sees all of the files where they reside, and it takes 30 seconds.
Couple of things to remember:
• Altering data in collection.nml will be indiscriminate across file paths, metadata, everything. So be SURE to use a disk name that is absolutely unique and whose name wouldn't be found as a string in ANY metadata throughout the collection. e.g., don't use a disk name like "Music" because this process would alter metadata within the collection.nml file that also uses that EXACT string; I am confident that "Music" would appear in the metadata of my collection many times, like in comments, song titles, album titles, etc. and I DON’T want that metadata changed. The name of my disk is "CEM Music" so I am confident that that EXACT string is not used in any metadata.
• The same is true of the disk name and colon in Windows environment. My disk is P: in the Windows environment. If any string of metadata exists in my collection that uses exactly "P:" then that too would be altered.
• You must have the same version of Traktor installed on both computers (Mac and PC).
• Obviously you must be using an external disk that you can plug into either computer, unless you did some jiujitsu / network drive mapping / google drive thing, which I suppose is possible.
• Be careful; one misspelling in the text editor and you’ll have created a mess.
Not rocket science. But LMK if any questions / comments.
