Hi @ambit8W8T5 ,

What AutoCAD version do you have on your Mac?

Do you have the same problem with other applications? Or just with AutoCAD?

Are you absolutely sure that network connection uses SMB protocol on your Mac?

Do the documents that you open in AutoCAD have external references attached? If yes - have you tried to open simple drawings without Xrefs?

I also have Synology NAS - basic DS_120 model - and don't have problems with opening drawings without Xrefs in AutoCAD.