N910u trying to write cert give this error

Hi team plz check log why i m getting this error

Code:

Chimera Mobile Phone Utility version: 10.26.1631 @ 2016-05-30

Printing phone history

Read / Write certificate
5/29/2016
11:43:49
PM

Read / Write certificate
5/29/2016
11:25:54
PM

[Read/Write certificate started]

Gathering phone info...
Collecting information. Be patient! Do NOT disconnect the phone!
Model: SM-N910U
Sales Code: TNZ
Country Code: New Zealand
Timezone: Pacific/Auckland
Android Version: 5.1.1 [LMY47X]
Build Date: Tue Dec 15 13:47:04 KST 2015
PDA Version: N910UXXU2COL2 [december 2015, rev2]
Phone Version: N910UXXU1COL1 [december 2015, rev1]
CSC Version: N910UTNZ2COL1 [december 2015, rev1]
Product Code: SM-N910UZWETNZ
HIDSw Version: N910UXXU2COL2/N910UTNZ2COL1/N910UXXU1COL1/N910UXXU2COL2
Board Platform: EXYNOS5
Modem Platform: XMM7260
Serial Number: RF8FB0XWEYZ
Imei: 355844060222140
Unique Number: CR20018F8440891
Connections: AT,MTP
Battery Status: 3.82V (38%)
Network Type: GSM
SIM Status: NOT_READY
Knox Version: 0
Warranty Bit: 1
Security Patch: 2015-12-01

Determining secure image format.
done.

Creating backup.
done.

Gathering cert informations
done.

Calculating key.
Chtool app run failed!
Finished at local time: [05.30.16 11:51:52]
WorkID: 11150319