Acctually I have some graphics on my application using Highcharts version 4.0.4. I would like if Highcharts have cross version compatibility and if I can upgrade to version 6 without rebuilt these graphics.
It's hard to say. Upgrade should go without any problems but it depends on which options and types of series you are using. It will be best if you just test it. Please, contact us if you find any problems.