Make sure you followed these steps:

https://support.apple.com/en-lk/guide/mac-help/mchl768f7291/mac
Select reduced security and enable this:
Select the “Allow user management of kernel extensions from identified developers” checkbox to allow installation of software that uses legacy kernel extensions.

Now you need to reinstall the SoftRAID driver. (Utilities menu)

After reinstalling the SoftRAID driver, (do not immediately restart) and go to System Preferences / Security to "Allow" OWC as an identified developer.

restart now.

Wait 5 minutes before connecting your disks. Do they mount?

I tried to mount my OWC thunderbolt 8 using soft raid. At startup Mac os Told me that he can't recognise drives...ok

I read the known issues FAQ and lower the security at startup as mentioned on the FAQ. Nothing more. same problem

I was able to see the drives but when selecting "MOUNT" it doesn't...

I re-installed Softraid and got a message telling me that the extension is out to date... great.

And now the mac restart suddenly after startup... several times... I've to disconnect the drives... scary to loose the RAID.

Any help ?

 Thanks