I see that Roon is on it, but just to clarify why I was going on about the disk format: It’s not that Roon removed support for any.
However, the new Linux kernel in the new RoonOS update has much safer NTFS support. One part of this is that it is more strict about NTFS disks being error free.
There have been several cases on the forum since, where it turned out that NTFS disks had once been connected to Windows PCs and removed by pulling the USB cable without properly doing the “safely remove” procedure of Windows. This leaves an “unclean removal” flag on the disk.
Earlier Linux kernels didn’t insist and mounted them anyway, which in some cases led to later NTFS corruption.
The new kernel, as used now by RoonOS, is strict about the NTFS requirements and refuses to mount such disks. The solution being to attach them to Windows again and doing the safe removal.
Here is one such case and Danny recommending exFAT for external drives:
Which was the recommendation previously as well. More: