We cannot add a new domain to server... It always says :

Unable to add new domain. Please try again or contact support.

What does the Helm error log show?

Is this your first domain? Did Helm create the sample domain when you set it up?

No there isn't any domains which created by helm...

If i'll remove and setup HELM again, can we solve the problem with this operation?

try posting whats in your helm error logs (C:Program FilesWebHost AutomationHelmLogs) and then maybe someone can see whats wrong.

#Software: HELM Control System
#Version: 3.1 Build 11
#Date: 2004-01-03
#Fields: date time source error
2004-01-03 04:09:36 CService.AllocateServicesEx Either BOF or EOF is True, or the current record has been deleted. Requested operation requires a current record.
2004-01-03 04:09:36 CService.GetAllocatedServicesEx Either BOF or EOF is True, or the current record has been deleted. Requested operation requires a current record.
2004-01-03 04:09:36 CWebsite.AddWebsiteEx Either BOF or EOF is True, or the current record has been deleted. Requested operation requires a current record.
2004-01-03 04:09:37 CDomain.AddDomainEx

looks like you are running .11 try updating to .12 and see if that help. The new update has loads of bug fixes in it.

I doubt this is an update issue. Check your resources (System Settings - Resource Setup). Make sure that each resource has a service allocated to it.

If so, make sure that all your plans and packages have the resources enabled on them.