uploading images using iPhoto

Since upgrading to Yosemite, I am unable to import images from my Canon EOS 1200D camera using iPhoto. I receive the message : Unreadable, The following file could not be imported. The file is in an unrecognisable format" I also tried to install the software that came with the camera but this does not work either and a message appears "ALERT - cannot be used with this version of this operating system. Can anyone advise please?