If CCU max exceeded, server reject join operation and returns operation error code 32757.
Use Photon.ErrorCode action to get last operation error code.
Other possible error codes:
OPERATION_DENIED = -3
OPERATION_INVALID = -2
INTERNAL_SERVER_ERROR = -1
OK = 0
INVALID_AUTHENTICATION = 32767
GAME_ID_ALREADY_EXISTS = 32766
GAME_FULL = 32765
GAME_CLOSED = 32764
ALREADY_MATCHED = 32763
SERVER_FULL = 32762
USER_BLOCKED = 32761
NO_MATCH_FOUND = 32760
GAME_DOES_NOT_EXIST = 32758
MAX_CCU_REACHED = 32757
INVALID_REGION = 32756
CUSTOM_AUTHENTICATION_FAILED = 32755
AUTHENTICATION_TOKEN_EXPIRED = 32753
PLUGIN_REPORTED_ERROR = 32752
PLUGIN_MISMATCH = 32751
JOIN_FAILED_PEER_ALREADY_JOINED = 32750
JOIN_FAILED_FOUND_INACTIVE_JOINER = 32749
JOIN_FAILED_WITH_REJOINER_NOT_FOUND = 32748
JOIN_FAILED_FOUND_EXCLUDED_USER_ID = 32747
JOIN_FAILED_FOUND_ACTIVE_JOINER = 32746
HTTP_LIMIT_REACHED = 32745
EXTERNAL_HTTP_CALL_FAILED = 32744
SLOT_ERROR = 32742
INVALID_ENCRYPTION_PARAMETERS = 32741