There are some printers that might create server instability spooler service component and as the result deny printing services as a whole for all connected users. If you don't have to define and implement any of the "required" methods they should still be represented in your class definition as comments.
This error message indicates that a printer error or communications error has been detected, and that this resulted in the writer ending abnormally. Then run the same command a second time to ensure the writer has returned to a stable state. If we find any other provider, other than Microsoft Software Shadow Copy provider, we need to remove it from the list.
Note: After deleting the Subscriptions key and rebooting, the subscriptions key is back in registry. Consult their respective engineers once.
Please check the providers using vssadmin list providers. Make a label for an uninitialized or error state. In this case we will have to enable VSS trace and check out further. Or, the user may not be authorized to the library in which the resources reside.
Avoid server instability with certain printers. Type is appended to make it clear this is not a class. You don't have to use a virtual destructor when: You don't expect a class to have descendants.
Make sure that the latest service packs and rollups are installed.