If you are using the User management search feature to look for a user account or return results for a group of users you may end up with no results as their are no accounts that match your search criteria.
You may want to think about the following when searching to help you find what you are looking for:
Amend search criteria - If you are running multiple searches you may need to remember to amend your search criteria slightly for the next search. You may have a date/learning path filter or a keyword in place that is restricting your results . You can always hit clear to start again from scratch. Searching for users
Check search values - There may be a typo or extra spaces in the values you are entering to search. Double check what you are trying to search for.
Widen search criteria - If you have your search values correct but perhaps the users name or email is incorrect on the portal then you may want think about searching by another value or searching for the domain, department or team the user is in to filter the results.
Archived users - You may want to change your search to look in Archived or All Users.