Description
A feature class or table can only be registered with the geodatabase once. There also may be a problem with the data specified to be registered with the geodatabase. Only feature classes or tables are supported.
Solution
Check the data properties of the data you attempted to register to make sure it isn't already registered with the geodatabase. Also, check to make sure it is a supported data type that can be registered to the geodatabase. Only tables that meet the geodatabase's preregistration requirements can be registered to the geodatabase.