samsung g920f patch cert fail

hi team i m trying to patch cert file giving me this error
phone problem was 35000006 imei i fixed imei but no network so i want to patch cert file
Waiting ADB device… OK
Reading phone info…
Model: SM-G920F
Android version: 6.0.1
Product code:
Phone version: G920FXXS3DPC2
PDA version: G920FXXS3DPE1
CSC version: G920FVFG3DPC1
CSC country code: UK
CSC sales code: VOD
HW version:
Phone SN: R58G414JLYZ
Modem board: SHANNON333
RF cal date:
Checking Super user right… true
Initialization zTool… OK
Running zTool, please wait… error (7.7.8)
Current version can not be patched

Done with Samsung Tool PRO v.26.9