System connection testing

Hello - Running EP6 6.0.15.0.0 WAS 6.4. I am trying to set up the system connections for the quality envirnment, and I receive the following error after testing the connection. We have checked the user and connection parameters, and they mirror DEV. Please advise on troubleshooting steps.

ERROR:

Test Connection with Connector

Test Details:

The test consists of the following steps:

1. Retrieve the default alias of the system

2. Check the connection to the backend application using the connector defined in this system object

Results

Retrieval of default alias successful

Connection failed. Make sure user mapping is set correctly and all connection properties are correct.