Hi, This is my first post so I'll ask for your forbearance. I've read this bug and experienced the issue with 9.0.0. I've now tried to use 9.0.1 and I am experiencing similar issues.
However, instead of presenting the CD-ROM error initially, the installation makes it passed CD-ROM check and then when attempting to save files to disk at approximately 24% (every time), the installer crashes. I have observed this in VM installs and local OS attempts using 9.0.1 non-free firmware MATE versions. About to try it with Gnome (standard). All instances use the full DVD image ~ 2.2Gb. Thanks for considering. Best --Z