Cannot copy and paste files over SMB but works on AFP Say I have mounted a sharepoint on /Volumes/Staff/.

I find that I cannot copy files from /Volumes/Staff/Folder1 to /Volumes/Staff/Folder2 and vice versa. I get the following error:


  
  Can't connect to the server because the name or password is incorrect.


The server is a Mac Mini running Yosemite with file server configured with Server.app.

Desktops are iMacs running El Capitan. They all connect via SMB by default when clicking on the Mac Mini icon on the sidebar.

I can replicate this problem on my MacBook Pro running El Capitan. I am connecting via afp://myserveraddress and smb://myserveraddress in Finder.app via "Connect to Server" menu.

I find that on my MacBook, copying and pasting files works while I am connected via AFP but not while I am connected via SMB.

But I cannot simply turn off SMB on the server, we also have Windows and Linux desktops that needs to connect to the server too.

What do I have to do so that Macs can connect to the server via SMB as a majority of the users would only be able to connect by clicking on the Mac Mini icon in finder rather than going through "Connect to Server" like me.
This has been resolved by upgrading the server to El Capitan. Copy and paste files on the sharepoint works now when accessing from MacBooks and iMacs running El Capitan.

Upgrade note, I find the order of steps for the upgrade important. The following are what I find the shortest and easiest steps when done in that order:


Backup. (I used Time Machine, but use whatever works for you.)
Run Install El Capitan.app, I had it saved to the local disk, otherwise run it from the Mac App Store.
Log back in after the upgrade has rebooted the server.
Run all El Capitan updates via App Store.
Update Server.app. (Via App Store.)
Open Server.app and ensure that file service is turned on. It was turned off in my case so I just turned it back on after double checked the file and sharepoints and their permissions.
Test with client computer with smb://myserveraddress in Finder.app via "Connect to Server" menu, this is so that you know it is working with SMB.


Out of the above, step 4 and 5 are the most important. In my case the latest version of Server.app was not compatible with older version of El Capitan (I didn't have the latest version of El Capitan as I didn't upgrade it from Yosemite through the App Store). So after upgrading to El Capitan, always install all updates available for El Capitan before proceeding to anything else.