- This is the My Cloud Home subforum which you have posted this subject, but your My Cloud EX2 Ultra has little to do with the My Cloud Home., having different OS, CPU and memory from each other.
- The error you are seeing with macOS 15 is that the smbfs (samba or SMB) that some macOS mounts are not compatible with the industrial standard SMB, causing file attribute error such as the ‘quarantine’ attribute shown below. These are well known and persistent bugs with Apple’s implementation of Samba which Apple has decided to make proprietary for financial gains (Apple wants you to use iCloud).
If you go to the My Cloud EX subforum as linked below, you may have a better chance of understanding the problem, but ultimately your solution may be addressed at the macOS subforum at Apple support.
How to mount a Samba directory through Te… - Apple Community?
