Backup Fails with file in use error

Database backup task failed: The process cannot access the file because it is being used by another process. This has been failing for quite a while.

eM Client 10.0.3530+f0b89b73a0 (Windows)

11:08:20 AM Database backup: Failed
11:08:20 AM MailClient.Scheduler.SchedulerException: Database backup task failed: The process cannot access the file because it is being used by another process.
—> System.IO.IOException: The process cannot access the file because it is being used by another process.
at System.IO.FileSystem.MoveFile(String sourceFullPath, String destFullPath, Boolean overwrite)
at System.IO.File.Move(String sourceFileName, String destFileName, Boolean overwrite)
at System.IO.File.Move(String sourceFileName, String destFileName)
at MailClient.Storage.Backup.BackupCompressionTool.Finish()
at MailClient.Scheduler.Tasks.BackupTask.PerformCompression(BackupCompressionTool zip, CancellationToken token, String tempDirectory)
at MailClient.Scheduler.Tasks.BackupTask.DoWork(IWin32Window owner, CancellationToken token, IScheduler scheduler, ReportProgress progressReporter)
— End of inner exception stack trace —
at MailClient.Scheduler.Tasks.BackupTask.DoWork(IWin32Window owner, CancellationToken token, IScheduler scheduler, ReportProgress progressReporter)
at MailClient.Scheduler.Scheduler.<>c__DisplayClass14_0.b__0(Object state)
GUIStatus_Exception_Reported = True

I made it work by starting the backup, opening the operations status window, then quitting the client until it was done. Maybe I should read the FAQ? If this is how it’s supposed to work, it should be in the FAQ, right?