Property Owner is not available for Database.

Sometimes when you try to open the properties dialog for a database the following error message is displayed:

“Property Owner is not available for Database ‘[<database>]’. This property may not exist for this object, or may not be retrievable due to insufficient access rights.  (Microsoft.SqlServer.Smo)”

This error happens when you are trying to access the database options and the database doesn´t have a database owner. This usually happens when the database owner user was deleted and a new database owner hasn´t been assigned to the database.

Assign a new user to the database using sp_changedbowner, for example:
use <databasename>
sp_changedbowner ‘sa’

The following query lists possible database owners that can be assigned to the database:
from sys.[databases]
inner join sys.[server_principals]
on [databases].owner_sid = [server_principals].sid

There are lots of other blogposts about this issue, here are a couple of examples:

Check Database Size

There is a standard SQL report that shows how much space a database is using. In SQL Server Management Studio for SQL Server 2008 R2 and newer, right-click on the database you are interested in and select Reports->Standard Reports->Disk Usage.

There is a good description of this report, including information about how to resize a Operations Manager database in the blog: