Retrofit Error "No transport of copies assigned to request for retrofit"

Hello Experts,

I have configured Charm in my Solution manager system(7.1 sp06) for my ECC system. The charm functionality is working fine. Now i configured retrofit functionality and completed all the prerequisites for the retrofit functionality. Now I made one urgent correction in my maintenance landscape and tried to retrofit it into implementation landscape but while retrofitting i am getting error as "No transport of copies assigned to request for retrofit". I have created one normal correction for my implementation landscape and created a request in which the retrofit will happen, but I am getting the error mentioned above. Can you please guide me why I am getting this error and provide me with the steps to resolve the error.

Thanks in advance.

Regards

Sunny