When the backup program Cobian runs a log is created telling you how many files are processed and how many of those are backed up. Viewing the logs is an easy way to check on your backup status. What happens when the logs are blank?
A setting within Cobian was changed. This can happen is you were infected or updated the software to a new version where only errors are reported. To change the setting, open Cobian, click on Tools, then Options. Click Log. You will see a track bar. It may be set to No Log or Log Errors Only. Move the track bar to the Normal setting and you will populate the log file.