Error while copying large files


I don’t understand i want to save a folder from my mac (50Gb) and i get this after a while

The operation can’t be completed because an unexpected error occurred (error code -50).

Should not do this ?

I have gotten that to, and I’m not sure what causes it. My suspicision is some type of system files / ACL issue. 

I have done two things in the past that was able to solve that for me.  Make a disk image file file on the source share and copy into that disk image.  Or using some type of copying / cloning software to find out which files are bombing out.  I’ve used Carbon Copy Cloner in the past.