ERROR_ACCESS_DENIED: Access is denied. [DirReaderPlus]

[cc12]

Good morning,
I have a NAS managed via raspberry with OpenMediaVault e
FreeFileSync is launched from a server running Windows Server 2012 and performs two mirror operations at different times and several times during the day.
The case reported in the attached log file has been occurring for some time.
I don't know exactly if it started from when I changed OMV version for NAS management. I tried to check the SAMBA service settings but I can't figure it out.
It should be noted that despite the error, the mirroring of the files is still carried out.
Do you have any advice or suggestions?
Thank you