Apple today is rolling out macOS Catalina that along with adding many impressive new features, is also serving as the death of iTunes. However, this is having an inadvertent affect on the lives of DJs.

According to The Verge:

[Along] with Catalina's removal of iTunes, users are also losing XML file support as all native music playback on Macs moves over to the official Music app, which has a new library format. XML file support is a popular organizational feature for DJs who use it to sort tracks into playlists and utilize the "Share iTunes Library XML with other applications" option to seamlessly transmit data between apps.

That has led to a big issue for DJs as popular apps like Serato and Traktor that relied on XML files won't be able to access the music. As The Verge notes, there is no fix and if you've used iTunes playlists to sort music for just about any software, Catalina will likely erase all that.

[A] previously reported fix saying users can manually export XML files in the Music app is incorrect. Essentially, if you're a DJ and you have put tons of time into sorting music in your iTunes playlists for whatever software you use, upgrading to Catalina will likely erase all your hard work.

If you are a DJ who used XML files for playlists, do not upgrade to macOS Catalina for the time being. At least not until developers roll out updates for their apps.