maxGamers is not in range of gamers that are supported in a network session. The XNA Framework supports multiplayer sessions between 2 and 31 players in a session for a Windows- or an Xbox 360-based game. On Zune, the XNA Framework supports a multiplayer session between 2 and 8 players in a session.
privateGamerSlots is less than 0 or greater than maximumGamers.
A different session already exists. There can only be one NetworkSession or AvailableNetworkSessionCollection in use at a time. You must dispose any previous session before you create a new one.
One of the following methods has been called, but has not yet returned results:
Note that you must wait for any of these methods to return before you can create a new network session. To support this, you may use the asynchronous methods BeginCreate, BeginFind, BeginJoin, and the corresponding EndCreate, EndFind, EndJoin methods to detect when the operation is complete.