@nareshjilla8055 as per the documentation: When you password protect a workspace, not only is a password applied, but the file scrambled against casual observation. I think you should check with Safe Software support

As per conversations with Safe: If you password protect your workspace, make sure the password is secured. It can not be retrieved by Safe or anybody else from the workspace. If the password is lost, the workspace needs to be recreated.

Sorry for the bad news.

One lightpoint, you can still run the workspace! Right click it and select open with 'Quick Translator'. You still have the option to change the parameters. It is just not possible to alter the workspace using Workbench.