Hello pedilover,
This may be also a corruption during downloading your ISO, this is why I encourage you to check the SHA1 values before using the ISO. By checking these values, you will be sure to get the correct (and unmodified) ISO

This may also be a lack of free space in your HDD/SSD, or a faulty HDD sector.
These are just ideas which crossed my mind

... anyway that you very much for the report !