ERROR: missing data for column when using \copy in psql

Three possible causes:

1. One or more lines of your file has only 4 or fewer space characters (your delimiter).

2. One or more space characters have been escaped (inadvertently). Maybe with a backslash at the end of an unquoted value. For the (default) text format you are using, the manual explains:

Backslash characters (\) can be used in the COPY data to quote data
characters that might otherwise be taken as row or column delimiters.

Output from COPY TO or pg_dump would not exhibit any of these faults when reading from a table with matching layout. But maybe your file has been edited or is from a different, faulty source?

3. You are not using the file you think you are using. The \copy meta-command of the psql command-line interface is a wrapper for COPY and reads files local to the client. If your file lives on the server, use the SQL command COPY instead.