Question / Problem:
Why would the column "Value Previous" in HistoryOfField" table sometimes have a blank or NULL value?
Answer / Solution:
This behavior occurs by design.
The "Value Previous" table in HistoryOfField remains NULL if there is no extraction done by KTM Server or Capture Recognition.
If there is a blank value, then this means that KTM Server or Recognition extracted a blank value. Also, if an operator during Validation enters a blank value then the 'HasBeenChanged' column will have a value of 1.