How do I fillet only one corner of a slab

Issue description 

When I select the slab and then use the Fillet/Chamfer tool, the Apply to all corners option appears grayed out, and I am unable to deselect it.

Solution

To fillet a single corner of a slab you need to,

1. Select the slab: Click on the slab you want to modify to make it active.
2. Edit the corner: Hover and left hand select the corner node you want to fillet.  The pet palette appears.

3. Choose the fillet option: From the pet palette, select the Fillet/Chamfer tool.
4. Set the fillet radius: Enter the desired radius in the Fillet Radius field that appears.
5. Uncheck the Apply to All Corners.
6. Apply the fillet: Click to confirm, and the fillet will be applied only to that corner.

This will round off just the selected corner without affecting the others.