Compatibility Between Different Releases of App
Designer
Starting in R2018a, the apps you save in App Designer have a new format. This new file
format might impact your ability to edit newer apps in previous releases, but it has no
impact on your ability to run them in previous releases.If you try to edit an app, created in R2018a or later, in an earlier release of App Designer,
the new format is not recognized after saving your changes. You see a message such as
this.To enable editing of newer apps in a previous release, save the app in the release-specific
format. Select Save > Save Copy As from any of the tabs in the toolstrip.In the Save Copy As window, select a type from the Save as Type drop-down list.Compatibility Between Different Releases of App Designer