finder – How do I fix Error Code -36 in Catalina?

I’m getting

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

when I try to copy or move certain fairly old files to an external drive, and have tried both deleting all DS_Store files and running dot_clean (with -mn) with out any success.

Is there another, perhaps newer or Catalina-specific method for getting rid of Error Code -36?