Once a field has been configured, you may re-open and edit the plugin's Configuration dialog:

Select Configure field from the right-click pop-up menu or
with the Field dialog open, right-click the field in Tree and select Configure field... from the pop-up menu.

To enable/disable plugins:

Tick/clear the Enable plugin check-box on the 'Layout' page of the Field dialog or
Click the Plugins button on the Tool-bar: Plugins 'engaged' button glyph indicates 'enabled' and Plugins 'disengaged' button glyph 'disabled'.
Select Enable field or Disable field from the right-click pop-up menu.


If a plugin attempts to modify a PDF document that is marked as not editable then the corresponding field is disabled and a warning given.