tonyw36 wrote:... Does this always happen?...
Not always, but some older versions of some software is incompatible with some
OS updates.
However, RoaringApps's compatibility review website indicates that Canon's EOS utility should work with OS X 10.9. Try downloading and installing the latest EOS software.
According to the relevant Canon USA support page, there is no EOS 5D Mark III software update available specifically for Mac OS 10.9 at present:
If your trouble continues, contact Canon for info on their planned update schedule or workaround help.
Message was edited by: EZ Jim
Mac OSX 10.9