SYMPTOM
Empty metric values are seen when derived elements are included on a report/dashboard with a calculation. This happens for metrics which use non numeric datatypes such as date. This can be seen in the below example with the day attribute, a metric defined as max(day) and a derived element subtracting two elements.
As can be seen in the example the metric has values for the individual elements but a null for the calculated derived element.
CAUSE
This is an intended change in Strategy 10.7 and up. It occurs as metrics are designed for numeric calculations and other datatypes are not being properly handled. In the below and above examples the date datatype is not consistent with the number datatype so the metric calculation cannot be done correctly.
ACTION
The functionality is working as designed as metrics for numeric calculations.
WORKAROUND
Convert the inputs of the metric to numeric before calculation so only numeric data is present in the metrics for analytical engine calculations such as derived elements.
The internal reference number for this is DE52300 and KB439632
