The Finder can’t complete the operation because some data in “filename.m4a” can’t be read or written. (Error code -36)" Can't fix

This has been asked before and nobody replied. I am hoping somebody does this time as this is causing me hours of wasted time and I can't solve it.

I am running OS Sierra and I am trying to move my iTunes music folders onto a Sandisk 64GB SD card (micro SD actually, in an SD adapter).

I have tried around 15 times, each time trying some tip I read about online, mainly the dot_clean function (on the source folder, destination volume, iTunes folder and dragged them out again etc). Nothing works, every time I get the error "

The Finder can’t complete the operation because some data in “filename.m4a” can’t be read or written. (Error code -36)"

N.B. THE FILE NAME CHANGES EVERY TIME. What I did the first few times was just delete the file, I can go without one track in the car! I did this many times and every time, the file transfer runs half the day then fails on a new filename unlike one seen before. I could go on forever like this so I tried to solve it using dot clean and this hasn't helped or changed any behaviour at all.

The SD Card is formatted to EXFAT, but I tried MSDOS too and that did the same thing.

Would greatly appreciate any ideas. The only thing I know of which I have not tried is the dot_clean terminal command which deletes ALL .DS_Store files on the whole machine. That seems a bit drastic to do before asking for advice on the forums, so I am waiting on that, also I am not sure it's actually a problem with .DS_Store files, as the filename is always an xxxx.m4a file.

Hoping someone can suggest something? thanks