Issues installing in MBP mid 2012 that already has Linux mint

Hi all.

I used my spouse MacBook to create a 32 GB bootable flash drive with oclp. I followed the site instructions but I keep getting that "no" sign from it when I pick "install" from the boot options. Can anyone help? I've tried 4 times until now. I've selected the 9,2 version in oclp... Nothing worked.