You shouldn’t see “unzipped files”. You should see either a .dtBase2 file or a folder with the database’s name. If it’s the folder, add .dtBase2 to the end of the folder name.
PS: How are you determining the database is “corrupt”?
It define a database file to be correupt when it will not open in DEVONthink. It is kind of greyed out and it will not open when double-click. It gives only a beeping sound.
I worked fine yesterday morning but yesterday afternoon, it would not open.