I am guessing, but the issue is likely to be related to https://docs.moodle.org/33/en/Password_salting
MoodleCloud
MoodleCloud Full Site Export - Passwords
ការពិភាក្សាត្រូវបានបិទ ដូច្នេះអ្នកមិនអាចឆ្លើយតបទៀតទេ។
I am guessing, but the issue is likely to be related to https://docs.moodle.org/33/en/Password_salting