I know this is the error which developers see most of the times. This is very basic error and it raises when we tried to access NULL reference object. But, What is if it comes while accessing STSADM? In SharePoint everyone knows the role of STSADM and the advantage of it. If you try to do some operation using STSADM tool and ends with the error "Object reference not set to instance of an object" then it is very difficult to trace as it is not giving us the enough information. But, with the experience, we get some ideas and solutions. Most of us know the resolution but I want to place everything what I know to my readers on this blog.
The user who runs the STSADM on the server should have access to the SharePoint Admin content database. If he don't have access, but he is administrator on server, has full access to central administration and farm administrator access then still no use. He should have access to the admin content database. Because whatever we do using STSADM then it is indirectly dealing with database only. So, user logged in should have access to database.
This is one of the main thing which we need to remember in administration side. Hope you liked it and you remember it forever. And mainly this scenario will come on environment where the farm server setup and database server is different from SharePoint server.