Hi,
At the beginning of the thread, you were having two issues:
1) you were trying to configure a vlan that was not present (the error message was requesting a vlan id)
2) the ipv6 address format was wrong
for example, I have the same error message below, vlan "myvlan" doesn't exist on the switch.
sw1.3 # configure vlan myvlan ipaddress fd01:976a:c200:6f1b:0:0:1::2/127
%% Invalid input detected at '^' marker.
%% A number within the range of 1-4094 is expected.
As for the IPv6 address, I'd not recommend the use of /127. For links, stay with /64, it's better that way.
https://tools.ietf.org/html/rfc5375
https://tools.ietf.org/html/rfc7421