.m4a files invisible

Hallo,
Serviio 1.4 doesn't show any m4a files. All are Apple lossless music files. Any suggestions?
My devices are Mac Mini with serviio 1.4 as server and Marantz NA7004 äs player. (Assett upnp makes these ones visible.)

Thanks for help

[DenyAll]

Were these file purchased from the Apple store? If so, they may contain Digital Rights management (DRM) that prohibits them being streamed by Serviio or any other media server.

Hello, Thx for answering,
No, i've made them by using XLD. There is no DRM.

[zip]

Apple lossless is not supported yet. There is an open ticket already.

Thanks, so I could wait Long Time
Any idea, when it will be available?
After All, Thanks for this Fine Server.