SYMPTOM:
Whenever saving a document in Strategy Developer 10.x users receive the error below:

CAUSE:
This occurs because there is dynamic text for a derived metric which does not have curly brackets around it {}. When these are not around the dynamic text, it will complain about the derived metric not existing in the metadata. In fact, this error is not incorrect as derived metrics are embedded objects which exist only within the datasets definition.

ACTION:
Place curly brackets {} around the derived metrics dynamic text.
NOTE: When metrics or derived metrics are clicked and dragged into the document as dynamic text, curly brackets are placed around them by default.