'Error to Delete File' received while updating CAS

Hi Guys can someone help me please. I loaded Stealth 2.32 which did not work. I then to go back the way and tried to load 2.20 and it didn't work. So I went back to the beginning and have successfully updated the CAM with 2.03, 2.04, 2.05, 2.06, 2.08, 2.09, 2.12, 2.14, 2.15, 2.16, 2.17....however when I attempt to load 2.18 I receive an error 'Error to delete file' and I cannot continue(I now realise that I can take a back up of the CAM file in order to reload and will do this from now on)but I cannot proceed at present. Any ideas I am using CAS studio 8.3+
thanks

Do I need to load the 2.03, 2.04 etc right up to date? or just load the latest

I have updated successfully with 2.32 and loaded new keys.bin. There is a file Diablo softcam key also do I load this one as well?
Do I need to set emulators 'on' and Auto PMT on
thanks