Empty disk not empty
Being a complete newbie to SoftRAID this might be my misunderstanding but when I run SoftRAID Easy Setup it's reporting an external USB connected disk as empty even though it's not.
FYI this disk is the information relating to the device:
Disk: USB External Physical Disk - GUID Partition Map
Volume: USB External Physical Volume - Mac OS Extended (Journaled).
Skip Easy Setup. Since mid Mojave, it has been breaking, so we are in the process of eliminating it from the next build of SoftRAID.
It should not report it as empty, unless there are no files on it, or detectable on it (It may be in DOS/NTFS format, for example, which still would be a bug)
Reset NVRAM (Like PRAM)
I suspect that will fix this. When disks start ejecting right after an OS X update, resetting NVRAM usually will fix the issue.
command option pr at startup.