There are some threads on radiocontrolzone about some problems with connecting t the casltelink... you might want to check these out and see if anything works.
I have not installed these updates or tried any of this...
But I did have problems once with a communication error like you are having.. and just had to keep trying it. you might even want to try rebooting the computer if nothing else works.
http://forums.radiocontrolzone.com/s...d.php?t=234593
http://forums.radiocontrolzone.com/s...d.php?t=233903
http://forums.radiocontrolzone.com/s...d.php?t=234394
Jammin CRT MM/Neu 1515 1700kv
Losi 8IGHT MM/Neu 1512 1900kv
Kyosho 777
T4 MM 5700
B4 LRP
XX4 MM 7700
old losi xxcr, MM4600 4s lipo 70mph+