I have been wrecking my brain with this issue for a few hours now. Googling endless looking for a solution. Problem occur when I try to copy files from my Mac to external HD, some folder works some does not! It will start copying then stop with the error “The Finder can’t complete the operation because some data in “HDR-JPG” can’t be read or written. (Error code -36)” (HDR-JPG is the folder name).
In short, it all comes down to the “._” in the filing system. You need to clean it with a dot_clean command from apple terminal.
1. Launch Terminal (Applications > Utilities) and type the following command, ***making sure*** to include a space at the end:
2. Select the folder on your Mac that is giving you trouble and drag it right to the Terminal window. A green cursor with a + symbol should appear before you release the mouse.
3. The path to that folder should have automatically appeared at the end of the Terminal command. For example, it might look like:
4. Press Enter/Return to run the command. It will appear as if nothing happened, but try copying that folder to a MS-DOS volume now. Finder should magically allow it to be moved with no problem!
5. Repeat the entire process as needed for other folders that won’t copy.
The solution I found is here at Macyourself.