I can't expose after tilting the machine

Hello, After calibrating the machine and performing the Cranio-caudal views, the machine freezes whilst angulating for the medio-lateral views and it gives a pop-up with a message " Exposure unit error [51135] : Pressing the button below will start restore processing on the exposure unit". After clicking the OK button i can continue the angulation but the exposure will be blocked until i restart the machine and do another calibration. Please how do i fix this?