According to the log file you have configured your backup skips the backup of all database tables. As a result of, there is no database backup created. This is an unexpected condition. Akeeba Backup tries to add the database backup file into the backup archive, but since this file does not exist (since nothing was backed up) you get a confused Akeeba Backup wondering why it cannot read that file. Hence the warning message.
Moreover, I noticed you appear to have excluded all files and folders of your site as well.
Because of that, your backup did run to completion, but it only contains the restoration script without any database content or files in it, making it useless.
Nicholas K. Dionysopoulos
Lead Developer and Director
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