Connection closed after too many TTL and Device does not respond

Dear All,

Kindly assist me with the below issue.

I was able to assign physical address to the KNX Dali Gateway (Hager TYA670D), but was not able to download Application Program. 

The error is  Device does not respond and sometimes it says "Connection closed  after too many TTL"

Kindly assist me to find a solution for this 

Thank you