I am currently doing some migration work for a client, migrating their Flex 3.5 application to Flex 4.5.

Occasionally, I will undoubtedly encounter bumpers…
This will be an account of those bumpers, and how I came to resolve them. This is not guaranteed to be the best solution, just the one that worked for me, usual caveats apply.

The application I am migrating is built of modules, and every time I ran the app I got an exception on UIComponent’s getStyle method. Nothing I did fixed this, until I found this link.

It describes a compiler flag, namely ‘isolate-styles’ which, when set to false, you can prevent merging of styles between the modules and the main application.