Sorry That Didn't Work Either
I wasn't expecting it to necessarily work. What happened? Exactly, please.
Also, please confirm my assumption about the circumstances of the first error message: "You're running version 0.9.9.11. With the File - Open dialog, you select the database file created with version 0.9.8.20."
You normally cannot open a database in an older version of the program after opening it (or attempting to do so) in a newer version. If you wish to revert to the older version, use a backup of the database that has only been used in that version. But there's not much point in going back to the old version—it's no longer supported. The plugin errors you're getting are probably the result of them not being updated for recent changes in the websites.
Do you have a backup or copy of the original database?