Backup failed: ERR


When I try to do a file backup I get an error: ERR
This are the only logs it produces:

27-10-17 17:24 INFO Starting unscheduled full file backup…
27-10-17 17:24 DEBUG Server: Connecting for filelist…
27-10-17 17:24 DEBUG Server: Waiting for filelist
27-10-17 17:24 ERROR Constructing of filelist of “Server” failed: ERR
27-10-17 17:24 ERROR Backup had an early error. Deleting partial backup.

Client: Windows SBS 2011
Server: Debian
UrBackup Client Version: 2.1.16
UrBackup Server Version: 2.1.19

The client is connected to the server.

Maybe this thread will help?: