Xqe-jdb-0001 Problem Establishing Connection. Please Check The Database Server ((install)) Access

The error XQE-JDB-0001: Problem establishing connection typically indicates a failure in the JDBC communication between IBM Cognos Analytics and your database server. Common Root Causes

Test login manually:

PostgreSQL (postgresql.conf):
listen_addresses = '*' (then restart)

Windows - check Services console

services.msc → look for SQL Server, OracleService, etc.