Re: BUG #14439: Trigger function fails with internal error after upgrade to 9.6

max.valjanski@gmail.com writes:
> Trigger function stopped working after upgrade from 9.5 to 9.6. Upgrade was
> performed via pg_upgrade.

After further thought I suspect this is the same issue discovered earlier
this month:

https://www.postgresql.org/message-id/flat/83shraampf.fsf%40is-it.eu

There's a patch here:

https://git.postgresql.org/gitweb/?p=postgresql.git&a=commitdiff&h=f4d865f22

If you're not prepared to rebuild with the patch, I think the only
short-term workaround is to recreate the table without a dropped
column.

            regards, tom lane