Hi,
All writer missing is a rare scenario. Usually it can be fixed by restart VSS services.
If there is still no luck to bring up writers, try to restart all services using following sequence:
Com+
Cryptsvc
VSS
Microsoft software shadow copy service
This normally works for Windows Server 2012 series and Windows Server 2016.
If still no luck, then jackpot. You might hit corrupted COM+ event system registry corrupted.
You can collect process monitor and see if there is multiple registry query not found. And see if you got such event in application logs:
The COM+ Event System detected a bad return code during its internal processing. HRESULT was 80070002 from line 200 of com\complus\src\events\tier2\service.cpp. This warning may be expected if the computer is low on resources. If the computer is not low on resources, and these warnings persist, it may indicate a problem in the COM+ Event System.
Volume Shadow Copy Service error: Unexpected error calling routine CoCreateInstance. hr = 0x800401fb, Object is not registered . Operation: Subscribing Writer Context: Writer Class Id: {4dc3bdd4-ab48-4d07-adb0-3bee2926fd7f} Writer Name: Shadow Copy Optimization Writer Writer Instance ID: {b799e1a9-4533-448b-a89c-045b138c4c35}
In that case, you can try to restore the corrupted registry from another good machine. Or you can get core engineer’s help. If you would like to open a case with MS, you may refer to the following link:
https://support.microsoft.com/en-us/gp/customer-service-phone-numbers
If the reply could be of help, please help to accept it as an answer, thanks for your cooperation!
Thanks for your time!
Best Regards,
Anne