Mike Skramstad When you mill a hybrid abutment crown out of the A16 e.max Abutment Block (one piece screw retained), it will undergo a step mill process all the way into the metal mandrel. This process will take upwards of 15 min and it will look like this as it's doing it:
After this step is completed, the burs will undergo another touch process. Sometimes little "flecks" of porcelain will get on the metal mandrel in the point where the burs are doing the touch process. This will error out your mill process and tell you that something when wrong (bur error, etc...). This is not the case usually. Just open the chamber and clean off the flecks of porcelain with your fingers and then continue. The milling process should finish fine.
Here is a final mill of two hybrid abutment crowns. Notice the step mill into the mandrel:
