NEED HELP Formatting CF card on Mac El Capitan

[joeray]

Hello Friends,
     I bought 2 new LEXAR 256GB 1066X CF Cards for my 5DMK3.   I went to format them in my Mac Book Pro Retina Disk Utility.  I recently updated the computer to El Capitan.  Well I tried a few different options and nothing works.  Can someone help me so I can use it with EX FAT...  Every time I put the CF Card back in my camera, it crashes...  Please help, I have a shoot tomorrow...  Thanks,   Joe Ray   at: [email protected]