Can you check the workbook again ? That error looks like it's a live datasource and the database server is not available
Hard to guess!!
There are multiple reasons for the cause of the issue.
Option 1 : If you are using the joins in your data source, try to create the new connection with same Joins. Sometimes renaming of fields used in the join condition might cause this issue.
Option 2: While publishing the workbook use prompt password option instead of embedded password. Provide the password on the server and check still issue exists.
Hope it helps!!