Finder freezing while copying files from external sources.

Thanks for your reply, digging more into the issue I have discovered that the freezing happens when I try to send data to an installed optibay with a secondary hard drive installed. The secondary drive seems to be working fine while reading but wont accept any incoming data being copied over ( starts then stalls). The optibay has been installed from another macbook pro 2011 (13") and didnt have any issues with that, so obviously since installing in my current macbook its hit this problem. Ive ruled out hard drive issues as I tried another and hit the same problem. Ive troubleshooted sharing / permissions and everything is set how it should, ive tried to send data via external drive, from the system drive, even from mac to mac transfer but all stalls after a certain point. The only other thing I can do as suggested is to reinstall High Sierra. A very annoying and frustrating problem.

Thank you,

Mark H

Update: After reinstalling High Sierra the issue has been solved.

Thank you for the help :)