Root Cause:
Oracle version prior to 12.2, the password should not be more than 30 characters. So when you try to perform a password reset with more than 30 characters it will show the above exception.
Solution:
Please change the maximum length of the password to 30 or below in the password policy.
Reference Link:
https://stackoverflow.com/questions/3085562/ora-00972-identifier-is-too-long-alias-column-name