SYMPTOM:
When a user tries to edit a metric formula by typing in the function name through the Metric editor, and the user may see the "Formula Incorrect" error when trying to validate a perfectly correct formula. Even if its the exact same formula as before, the user still may experience this error.

CAUSE:
One reason why this may be happening is because a user created a new object named "Sum", which in turn is stored in their metadata. Strategy is incorrectly linking the new "Sum" object to the "Sum" function.
Please refrain from naming objects with general names such as "Sum". This goes for all function names.
STEPS TO REPRODUCE:
1. Create a fact and name it "Sum"
2. Edit any metric . Type in the "Sum" function.
3. No matter what formula you put, it will always be incorrect
ACTION/WORKAROUND:
Rename the object to something with more detail.
or
Use the "Insert Function" button when creating metrics. This will guarantee that the "Sum" is being linked to the correct Sum function.