FIRST STEP in upgrading Illustrator if using Cutting Master;
Head to the download site for Cutting Master and check which version of OS are supported and which Illustrator versions, if listed.
http://www.graphteccorp.com/support/software/cuttingplotters.html
If all OK, then update Illustrator before you update Cutting Master.
Updating Illustrator breaks the links to Cutting Master.
If you have already updated Illustrator and your version it isn’t compatible, then you will need to downgrade Illustrator to a supported version.
Uninstall Cutting Master and reinstall a fresh copy. Download the latest version from;
http://www.graphteccorp.com/support/software/cuttingplotters.html
If you just install the latest version of Cutting Master it will keep old settings unless you tick the option to delete old data.
Download a pdf version here: