I've tested the app, and it works just fine.
I'm guessing this has something to do with the fact you're writing the encrypted text to the database, and reading it back for decryption, and looking at Configuration.xml~ (the backup file) included in your sample, I see you're using postgres, whereas I've tested using the default hsqldb setup.
I'm guessing there's something wrong with the postgres configuration (at least with the table/column used for the encrypted text).
Compare the encrypted text you write to the text returned when you read it back, and you'll probably find it's not the same.
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