After upgrading from PostgreSQL 9.2 to 9.3.4, I was no longer able to access my database from psql or pgAdmin:
FATAL: could not access directory "pg_tblspc/16639/PG_9.3_201306121/16843": Permission denied
- This directory exists.
- All user groups have full permissions to the directory as well as all its parent directories.
PostgreSQL now requires a NETWORK SERVICE account, which it did not create. Since I was using PostgreSQL on the Home version of Windows 7 (64-bit), I cannot access the Local Group Policy Editor.
One possibility is to transfer your database to a different OS.
I solved it by restoring my database from production.