1. Make a dtable. 2. Use "Set the value of field" just to insert a new fact in RHS ( used a fact with a boolean field ) 3. The column can be edited 4. To change the fact variable name I click edit on the "Action columns" list for the column 5. To change the variable name create a new Fact Pattern with the new variable name. 6. Select the same field as before and save changes Clicking on the insert column should allow editing. Instead you see the "Unexpected error" popup with "An unexpected error happened. Please try again in a few moments."