GE Washer won't agitate

My GE washing machine seems to be operating fine until it is supposed to agitate. The machine hums but will not turn the agitator. It drains and spins normal, but won’t turn the agitator. Any suggestions on how to fix?:confused:

I cannot get your model number to come up, please check it and post if a correction is needed.

If this is a basic GE top loader, take off the agitator and check the drive block underneath it.

Thanks