Adding machine in network to take back up showing error

Hello All,
I had tried to add a machine in the network using the machine name and IP address it shows error, but gets added to the main server which takes the back up showing "Error". I am able to ping the machine and also the services of acronis are running in the target machine. I have tried stopping the service in the target machine and started again it was successful in running the service again in the target machine. I now again tried to add the machine in the main server still the error exist. First time when it was added it was showing "OK".
Below are the screen shots.

Regards