I have a Logic file that just hangs up and will not copy over

I have three hard drives and I usually back up my logic files when I’m finished with them. I slide one over to the other drive and it asked me if I want to replace. I say yes and it copies. This has worked for years. I have a file that just hangs up and will not copy over so now I can’t make a copy of my latest file.

[Re-Titled by Moderator]