Comodo backup 4.3.6 scheduled backup does not run

I have Comodo Backup 4.3.6 installed on a Windows 8.1 laptop. No problems with manual backup. But backup does not run at scheduled times, set every 4 hours. Instead I get a message “Scheduled Task XYZ has been missed, Do you want to run it now”. This is the Run option I have selected. It will run when I click OK. I installed the software as an administrator and I also open it as an administrator. Uninstalling and reinstalling has not helped. Debug file and SynchronizationService.exe.log attached

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