SYMPTOM:
After a user executes a report it returns data but with a metric missing. This issue occurs even though 'View' permission for the Everyone group or the user itself is added to the ACLs of metrics as shown below:

Administrators that execute the report do not see this problem since it is user-specific.
CAUSE:
The Access Control List (ACL) for the report might not have been updated.
ACTION:
In the Project Configuration -> Project definition -> Security dialog box for a project click the "Update ACL for Reports" as shown in the image below:

For further information on which objects are modified by clicking 'Update ACL For Reports' refer to the following Strategy Knowledge Base document:
KB5700-7XX-1644 - Which objects are modified by clicking 'Update ACL For Reports'?