I've began to have this problem as well. Just started with the new server/SQL move? I'm only running CM Dual miner.
I can also confirm the email is not working once a rig goes offline
Just moved to Windows 10 and I'm also receiving an error when trying to create the startup task
"Unhandled Exception: System.IO.FileNotFoundException: The system cannot find the file specified. (Exception from HRESULT: 0x80070002)
at Microsoft.Win32.TaskScheduler.V2Interop.ITaskFolder.RegisterTaskDefinition(String Path, ITaskDefinition pDefinition, Int32 flags, Object UserId, Object password, TaskLogonType LogonType, Object sddl)
at Microsoft.Win32.TaskScheduler.TaskFolder.RegisterTaskDefinition(String path, TaskDefinition definition, TaskCreation createType, String userId, String password, TaskLogonType logonType, String sddl)
at Microsoft.Win32.TaskScheduler.TaskFolder.RegisterTaskDefinition(String path, TaskDefinition definition)
at MultiClient.Program.createTask()
at MultiClient.Program.Main(String[] args)"
EDIT: Figured it out. I upgraded from Windows 7 to Windows 10. The upgrade did not delete my previous scheduled task. I had to get rid of it in task scheduler, and I was then able to re-create it without issue
Are you run with administrator privileges?