Server Stop doing backups

Hi Guys, After a month working perfectly, the server just suddenly stopped performing automatic backups, i try to stop the service, restart the server machine which is installed in a Windows 2012 r2 Server. I am able to do manual backups, but it will not start itself the next day. I left it for about a week and nothing happens.

Could you have a look at the server log file? See here where to find it: Having problems with UrBackup? Please read before posting

Before I saw your post I had click on Cleanup_database to see if it solve the problem. Here is the partial log

Destroying all databases…
2016-01-25 12:23:22: Created new database connection for urbackup/backup_server.db
2016-01-25 12:23:22: Creating files Indices…
2016-01-25 12:23:22: Started UrBackup…
2016-01-25 12:23:22: Created new database connection for urbackup/backup_server.db
2016-01-25 12:23:22: Removing temporary files…
2016-01-25 12:23:22: Recreating temporary folder…
2016-01-25 12:23:22: Testing if backup destination can handle subvolumes and snapshots…
2016-01-25 12:23:22: Backup destination cannot handle subvolumes and snapshots. Snapshots disabled.
2016-01-25 12:23:22: Testing if backup destination can handle filesystem transactions…
2016-01-25 12:23:23: UrBackup Server start up complete.
2016-01-25 12:23:23: Creating SOCKET…
2016-01-25 12:23:23: Looking for old Sessions… 0 sessions
2016-01-25 12:23:23: done.
2016-01-25 12:23:23: Server started up sucessfully!
2016-01-25 12:23:23: Created new database connection for urbackup/backup_server.db
2016-01-25 12:23:23: Created new database connection for urbackup/backup_server.db
2016-01-25 12:23:54: New Backupclient: spar-pc
2016-01-25 12:23:54: New Backupclient: Server-Web
2016-01-25 12:23:54: New Backupclient: DVRries
2016-01-25 12:23:54: New Backupclient: Mast-PC
2016-01-25 12:23:54: New Backupclient: SDrlock
2016-01-25 12:23:54: Sending Identity to client “spar-pc” failed. Retrying soon…
2016-01-25 12:23:54: Sending Identity to client “Server-Web” failed. Retrying soon…
2016-01-25 12:23:54: Sending Identity to client “DVRries” failed. Retrying soon…
2016-01-25 12:23:54: Sending Identity to client “SDrlock” failed. Retrying soon…
2016-01-25 12:23:54: Sending Identity to client “Mast-PC” failed. Retrying soon…
2016-01-25 12:23:54: Created new database connection for urbackup/backup_server.db
2016-01-25 12:23:54: Created new database connection for urbackup/backup_server.db
2016-01-25 12:23:54: Created new database connection for urbackup/backup_server.db
2016-01-25 12:23:54: Created new database connection for urbackup/backup_server.db
2016-01-25 12:23:54: Getting client settings…
2016-01-25 12:23:54: Created new database connection for urbackup/backup_server.db
2016-01-25 12:23:54: Sending backup incr intervall…
2016-01-25 12:23:54: Getting client settings…
2016-01-25 12:23:54: Created new database connection for urbackup/backup_server.db
2016-01-25 12:23:54: Getting client settings…
2016-01-25 12:23:54: Created new database connection for urbackup/backup_server.db
2016-01-25 12:23:54: Sending backup incr intervall…
2016-01-25 12:23:54: Getting client settings…
2016-01-25 12:23:54: Created new database connection for urbackup/backup_server.db
2016-01-25 12:23:54: Sending backup incr intervall…
2016-01-25 12:23:54: Sending backup incr intervall…
2016-01-25 12:24:23: Downloading version file…
2016-01-25 12:24:23: Downloading server version info…
2016-01-25 12:24:43: HTTP: No available slots… starting new Worker
2016-01-25 12:24:51: Created new database connection for urbackup/backup_server.db