Question Spanning drives problem: "The operation is not supported by the object" ?

[New User 337]

I have a 16T and a 10T drive and want to span them in Win 10 Pro using Disk Manager for (approx) 26T. They are both formatted as NTFS and the partition table is GPT. I go through the Win 10 Disk Management steps to span or stripe them and regardless of what I do I get a Virtual Disk Manager error message: "The operation is not supported by the object".

I've tried:
spanning and striping (preference is spanning),
changing "Allocation unit size",
quick and standard formatting,
and likely a couple of other things I can't think of at the moment. I get the same message every time with no change in the program behavior in any mode tried above.

The drives are Toshiba (16T) and a Seagate Exos 10 (10T), mounted in an external cabinet connected to a PCIe to USB C 3.2 Gen 2 card.

I've spanned a lot of drives before both internal and external without issues but nothing this size. The cabinet and card are new too so there could be something I don't know about their interaction with Win 10 or the drives.

Edit:
1. I tried to span two 10T drives in the same cabinet with the same error message. I'm not entirely clear what that is telling me but it might eliminate size as an issue because I've spanned these two drives together before in another cabinet.

Any ideas to get these drives to span? Thanks

 

[kerberos_20]

well, dynamic disks arent supported on removable drives (usb)
that another cabinet was probably sata or sas i suppose

you will neeed to hook those drives fisrt with sata, convert them in disk management to dynamic disks, then hook them with usb
that should make it working

 

[New User 337]

kerberos_20 you are right about dynamic disks and USB. On the convert first and install them in the tower, I think I tried that and it didn't seem to work. I didn't do any deep troubleshooting so it might have if I had kept working on that as a solution. In the end I returned it and am looking for a SATA tower now. Thanks for the reply.