Why can I not see any vulnerabilities ("No data to display") when clicking on a portlet or widget on the AppCheck dashbaord?

Context

The AppCheck customer portal (https://scanner.appcheck-ng.com/) can be configured to display one of a number of "portlets" or "widgets" in the primary dashboard (left) or Quick View (right) sections.

Each portlet can display data, and some widgets such as "OWASP Top 10" and "Vulnerabilities Status" portlets contain clickable regions that can be clicked on to view the underlying data about the vulnerabilities relating to the counts displayed.

Problem

In some circumstances, a customer logged in to the ApPCheck customer portal will be able to see a non-zero count (eg "3") for a given vulnerabilities type in a portlet, yet when they click on this to see the vulnerabilities this relates to, they are returned the message "No data to display".

Solution

Typically this will occur due to a permissions mismatch, where the user in question has not got permissions to view the vulnerabilities in question. This can be resolved by having a customer "admin"-level user add the user in question to be a watcher on individual scan (or scans) in question, or define/amend the user group membership in Users -> User Groups so that they are able to see all scans (and hence all vulnerabilities) on the account.