Doing some routine maintenance and first time changing out the tangential blade. Turned off the machine, tried to twist open the tangential blade holder from the shaft. However it was not budging. Tool two pliers (one to hold the bottom and one to turn the top of the blade holder )and it started to turn. However then a pin out out and the top half (black part) of the holder came off leaving the metal part of the holder still in the shaft. Tried to get it out w/ pliers but would not move at all. Anyone else experience this?