N920T Ztools Error Please Help

Hey I have been working on this N920T for awhile never had a problem before with this.. I downgraded from COK to COI and still giving an issue.
If anyone has any ideas that would be great.

Operation: Unlock
Selected model: SM-N920T
Software version: 24.5

Waiting ADB device… OK
Reading phone info…
Model: SM-N920T
Android version: 5.1.1
Product code: SM-N920TZKATMB
Phone version: N920TUVU2COI5
PDA version: N920TUVU2COI5
CSC version: N920TTMB2COI5
CSC country code: USA
CSC sales code: TMB
HW version: REV0.2
Phone S/N: RF8G92J86MX
Modem board: SHANNON333
RF cal date: 20150925
Checking Super user right… true
Initialization AT RIL… OK
Check version… OK
Initializating zTool… error

Done with Samsung Tool PRO v.24.5