Find missing data in a column

Hi,

I have a database in PostgreSQL 12 on Windows. It has > 8,000,000 rows. 
I want to copy this database to PostgreSQL 10 on Slackware Linux. I used 
this command to get the data out of the Windows database:

"C:\Program Files\PostgreSQL\12\bin\pg_dump.exe" 
--file="C:\Users\Nightrunner\DOCUMENTS\programming\pg_out\ebird_sptl_all.dump" 
--host="localhost" --port="5432" --username="postgres" --password 
--verbose --format=c --no-owner --no-privileges --dbname="ebird_work" 
--table="p_loc.ebd_sptl"

On Slackware, I first:

su postgres

Then try:

psql ebirds

SET SEARCH_PATH TO p_loc;

COPY p_loc.ebird_sptl FROM 
'/nt-d/projects_and_data/ebd_OR/ebird_sptl_all.dump';

That fails with

missing data for column "COMMON_NAME"

I understand this means there is a problem with one or more rows in the 
column referenced. This is a column of text. How do I find the error(s) 
in question?

Cheers,

John

-- 
Enlightenment is ego's ultimate disappointment.
-Chogyam Trungpa