You can't open the .twb file that saved in your computer and also you can't open the .twbx file also that saved in your computer.
Below is the message will appear when you try to open .twbx file from Tableau Public from File menu option and select open.
Means .twbx Tableau file should be saved in your Tableau Public account.
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and is my public password the same as my Tableau.com password?
ps and reader let's you view, but not edit?
No I guess, I think there are two different passwords with usernames. Please check once and test.
Yes in Tableau Reader you can view the .twbx file with source as extract if your data source is RDBMS (ex: SQL Server, MySQL etc), but you can't edit your workbook in Reader.
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