Here are some common errors and potential solutions to the problem.
Server was unable to process request. ---> Retrieving the COM class factory for component with CLSID{0000007C-0000-000F-1000-000AC0BA1001} failed due to the followingerror: 800703fa Illegal operation attempted on a registry key that has been marked for deletion. (Exception from HRESULT: 0x800703FA).
This problem is caused by Windows "deregistering" the AcombaDLLs during the logout of the user associated with the ApplicationPool of the AcombaWebService.
To fix this problem, select a system user on the ApplicationPool or change the security settings as mentioned in the following link.