This article explains why we get the error "Length 64 is not within range (1..63)" when configuring the address book's address name

user@srx# set security zones security-zone Untrust address-book address www.56_123456_123456_123456_123456_123456_123456_123456_1234.com
        ^
Length 64 is not within range (1..63) at 'www.56_123456_123456_123456_123456_123456_123456_123456_1234.com'

This is an expected behaviour as it is the limit of SRX (63 characters) for any address name in the address book.
There is no workaround to modify this.

Please note that the limit for the address book's address name is 63.

set security zones security-zone untrust address-book address <> --> here the limit is 63

However, the number of characters in a dns-name will be 253
set security zones security-zone untrust address-book address example2 dns-name <> --> here the limit is 253