mediawiki 1.21.3, postgresql 9.1.9, PHP 5.4.4-14+deb7u5 (apache2handler), internal wiki not internet accessible. Fresh installation (not an update).
The column us_props is missing from the mediawiki.uploadstash table. This causes the error:
ERROR: column "us_props" of relation "uploadstash" does not exist
I tried deleting the table and recreating with php maintenance/update.php, but it doesn't add it. I created it in psql:
alter table mediawiki.uploadstash add column us_props bytea null;
and now I can upload files.
Hope this helps.