Message shoes in zt: NestPlus Message : otp connection : 0 -- recovery attempt failed, trying again

when i login to zt the message shoes the nest plus login successfully but message is showing in message box

NestPlus Message : otp connection : 0 -- recovery attempt failed, trying again

and after some minutes message showes on message box

NestPlus Message : otp connection : 0 -- no of reconnection attempts limit breached. shutting down.

i have activate the nestplus api and problem is that when amibroker generate any signal for buy sell order is not show in nest plus api orders generated window

so please suggest me how can i solve this problem 

thanks