An error has occurred in the TNG software. What to do:
If you just installed an upgrade, you might have skipped part of the installation instructions. Go back to the upgrade readme page reread the instructions. Pay special attention to the database structure step.
If you just installed TNG for the first time, you might still need to create the database tables. Return to the readme.html page to find that step.
If you are the site owner, you may contact TNG support for further assistance with this problem. Please copy the query below and paste it into your message.
Query: SELECT f.familyID, h.personID, h.lastname AS 1st_lastname, h.firstname AS 1st_given_name, h.birthdate as birtdate1, h.sex AS gender1, w.personID, w.lastname AS 2nd_lastname, w.firstname AS 2nd_given_name, w.birthdate as birtdate2, w.sex AS gender2, f.living, f.gedcom FROM tng_families AS f LEFT JOIN tng_people AS h ON f.husband=h.personID LEFT JOIN tng_people AS w ON f.wife=w.personID WHERE h.sex=w.sex ORDER BY familyID LIMIT 50
The SELECT would examine more than MAX_JOIN_SIZE rows; check your WHERE and use SET SQL_BIG_SELECTS=1 or SET MAX_JOIN_SIZE=# if the SELECT is okay