Operator gave hoist up command, Brake release felt sudden and hard, Followed by a very slow hoisting up or down. Some cases the crane would kick the operator out shortly after the hoist function was given. When the crane faulted E.65 was displayed on the KEB hoist drive.
New Encoder was ordered
Hoist drive was placed in to Degraded Mode 
Replaced hoist Encoder, 
Took hoist drive out of degraded mode and normal operation resumed.
Do you have a picture of the encoder location?
Is it wired directly into the drive?
Do you have any pictures of the drive with cover off for location of shunt switches?