Which version of Tableau server are you using? Is it installed on a Mac or Windows OS?
Tableau server needs the correct drivers to access various datasources (like MySQL), and sometimes you need to install them after you have installed Tableau Server
All the documentation can be found on the link in that error
Thank you Jessica for your quick help.
We are using Tableau Server Version: 10.0.0 (10000.16.0812.0001) 64-bit.
Will install MYSQL drivers on Tableau server and will get back to you if we face any issue.
Thank you very much.