GSM Shield problem

Can Someone help me with this error I'm getting when I'm trying to connect my gsm shield to my arduino mega project..

Arduino: 1.6.9 (Mac OS X), Board: "Arduino/Genuino Mega or Mega 2560, ATmega2560 (Mega 2560)"

WARNING: Spurious .github folder in 'DHT sensor library' library
In file included from /Users/stephen/Documents/Arduino/libraries/Keypad/src/Keypad.h:36:0,
from /Users/stephen/Documents/Arduino/Master_code_working_January/Master_code_working_January.ino:8:
/Users/stephen/Documents/Arduino/libraries/Keypad/src/Key.h:41:15: error: redeclaration of 'IDLE'
typedef enum{ IDLE, PRESSED, HOLD, RELEASED } KeyState;
^
In file included from /Users/stephen/Downloads/Arduino.app/Contents/Java/libraries/GSM/src/GSM3MobileNetworkProvider.h:37:0,
from /Users/stephen/Downloads/Arduino.app/Contents/Java/libraries/GSM/src/GSM3MobileClientService.h:37,
from /Users/stephen/Downloads/Arduino.app/Contents/Java/libraries/GSM/src/GSM.h:42,
from /Users/stephen/Documents/Arduino/Master_code_working_January/Master_code_working_January.ino:4:
/Users/stephen/Downloads/Arduino.app/Contents/Java/libraries/GSM/src/GSM3MobileAccessProvider.h:37:36: note: previous declaration 'GSM3_NetworkStatus_t IDLE'
enum GSM3_NetworkStatus_t { ERROR, IDLE, CONNECTING, GSM_READY, GPRS_READY, TRANSPARENT_CONNECTED, OFF};
^
Board at /dev/cu.usbmodem1421 is not available

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