You have too many entities placed in your map, and because of that, when you load bots into the map, the engine will overflow. The max amount of “edicts” that the engine can handle is 2048, and any more than this number will crash the engine.
The only fix to this is to reduce the amount of entities in your map. Do you have excessive amounts of point_spotlights or other visual effects like env_lightglow? Because it is extremely easy to flood the engine with these, and these would be the first thing I would scale back on.
For more information on Edicts: https://developer.valvesoftware.com/wiki/Entity_limit