The error code XQE-JDB-0001 is a critical connection failure within IBM Cognos Analytics

Check the XQE log files (found in the Cognos install directory under ..\logs\xqe

Locale Settings: Non-English locale settings for certain users can sometimes trigger this connection failure.

jdbc:mysql://host:3306/db?connectTimeout=30000&socketTimeout=60000

Test in Administration Console: Log in to Cognos Administration and test the data source connection specifically for Dynamic mode to see if it provides more detailed metadata on the failure.