Hello Sandesh,
I would greatly suggest to create a support ticket regarding this concern so they can assist you on registering the environment.
Regarding your error on #2 "String or binary data would be truncated" it's quite vague but that error is commonly thrown if your characters are greater than the amount allocated on the attribute.
Perhaps the value of what you are trying to register has more characters than what is specified on the attribute's length.
Regards, hopefully you get to resolve this issue soon.
Jose