I have a problem regarding my CT device (Dual GE)

I have this error recurrent and need to restart my CT device with each case !! Scout scan error .. Code : 20-1001-48 error detected by : OGP aperture width is out of specification on scout scan. Aperture error . Code . 20.1020.03 error detected by : OGP encoder pulse input from aperture is out of specification while setting aperture width