NEED HELP formatting my CF CARDS in El Capitan Disk Utility !!!

[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: joeray@alaska.net

[nikfreak]

format card in cam? btw: no need to double post

[joeray]

I did format in the camera first.  Then I used Disk Utility to set EX FAT.  This is where I am having problems...  Any advice... 

[joeray]

Folks, I’m still having trouble and don’t know why...   When I received a new Lexas CF Card 256GB 1066x, I formatted the card in my camera (5DMK3).  This works fine but I want to format to EX FAT by using Disk Utility in my Mac Book Pro retina...  Unfortunately, I updated my OS X to El Capitan.  Now when I try to erase and partition to EX FAT, I do not get the same results.   When I insert the card back in my camera, the camera skips frames and will stop after a minute or so with no recording on the disk.   So Please offer me advice how you folks with El Capitan are getting your CF Cards to work... What am I doing wrong?     Thanks,  Joe Ray  at:  joeray@alaska.net