Error Datasource Name Not Found And No Default Driver Specified

Description

The error, "Datasource name not found and no default driver specified" is displayed when attempting to open a label in On-Demand Print Client.

Solution

This error can occur after adding an advanced connection string (to bypass a database login prompt) for multiple database key fields on the same label. 
  In this case, the structure of the Advanced connection string MUST include the DSN (Data Source Where data is extracted to produce labels. Loftware Label Manager provides a variety of data sources, including the keyboard, a database, serial number, a formula, via the UCC or UPN Wizard. For RFID labels and tags, data can come from the Keyboard data source or by configuring data blocks using the Block Configuration data source. Name).

Example

DSN=loftware;UID=scott;PWD=tiger.

Note: The above is the solution only if the error is caused by the connection string. This error may occur for other reasons.