This data definition statement specifies a table, view, index, or synonym that is owned by another user or grants/revokes a privilege as another user. Any of these things requires Database Administrator privilege, which you do not have on this database. If you intended to work on objects that you own, review the punctuation of the statement. At some point in it, you have qualified a name with the user ID of another account. Otherwise, get a DBA to grant you DBA privilege or to perform this operation for you.