Once an object has been extruded, you cannot apply certain effects and changes to it, such as:
- Adding or removing text
- Adjustment of fills
To adjust these properties you will need to first remove the extrusion by toggling the '3D' button on the Extrude Tool infobar.
Then make the neccessary adjustments and toggle the button again to re-apply the extrusion.
N.B The properties of your extrusion will be remembered, so it will maintain the same appearance it had prior to being removed.