writing cert failed sm-n910p

i get a error when i write cert to sm-n910p

INFO : 1/23/2016 3:53:35 PM > Platform: Samsung Android
INFO : 1/23/2016 3:53:35 PM > Selected port: COM9
INFO : 1/23/2016 3:53:35 PM > Selected model: SM-N910P
INFO : 1/23/2016 3:53:50 PM > Selected file: C:\Users\Cookie*******2\Downloads\Cert-SM-N910F_355324060515397.cert
INFO : 1/23/2016 3:53:50 PM > Detected phone model: SM-N910P
INFO : 1/23/2016 3:53:50 PM > Firmware compiled date: Thu Jul 16 20:00:24 KST 2015
INFO : 1/23/2016 3:53:50 PM > PDA version: N910PVPU4COG5
INFO : 1/23/2016 3:53:51 PM > CSC version: N910PSPT4COG5
INFO : 1/23/2016 3:53:51 PM > SW version: N910PVPU4COG5
INFO : 1/23/2016 3:53:53 PM > Phone SN: 00000000000
INFO : 1/23/2016 3:53:53 PM > Android version: 5.1.1 (LMY47X)
INFO : 1/23/2016 3:53:53 PM > Checking Root:
INFO : 1/23/2016 3:53:54 PM > Phone is Rooted.
INFO : 1/23/2016 3:53:54 PM > Checking Certificate file…
INFO : 1/23/2016 3:53:54 PM > Certificate file successfully checked
INFO : 1/23/2016 3:53:54 PM > Writing Certificate…
INFO : 1/23/2016 3:53:54 PM > Writing new phone IMEI…
ERROR : 1/23/2016 3:54:15 PM > Writing Certificate failed