Both Teams are Full error

This error in Counter-Strike: Source and Counter-Strike: Global Offensive occurs if the game cannot find an available spawn point, either because you forgot to place them, or because those you placed are invalid.

You need to have both info_player_counterterrorist and info_player_terrorist entities in the map, or the game will not be set up correctly.

If both spawn points has been placed, check the Developer Console. If it reports that your spawn points are invalid (for example Invalid terrorist spawnpoint at (<x>,<y>,<z>)), the problem is usually that your spawn point entities are intersecting another surface in the map, usually the ground. Unlike Half-Life 2 and Half-Life 2: Deathmatch spawn point entities, Counter-Strike: Source spawn point entities will intersect the ground if not placed a couple of units above it. Try moving the entities up a little bit (atleast 16 unit above the ground, more than 16-32 unit from wall or another spawn entities) to make sure that they are not intersecting with anything.