Flash Builder debugger/profiler doesn't connect to Flash Player
If you use Internet Explorer (IE) Modern UI browser for debugging or profiling applications, close the browser window before you debug or profile the same application. If the earlier session of the browser window isn't closed, the application doesn't reload. And, the debugger/profiler doesn't connect to Flash Player.
Application code changes are not displayed in Internet Explorer Modern UI browser
When you want to rerun an application after making changes, close the Internet Explorer Modern UI browser before rerunning the application. Otherwise, any newly added components or changes in the application file are not displayed in the browser.
A "Launch Failed" message appears when launching the application in Modern UI mode
If your default browser doesn't support Modern UI mode, and you try to launch the application in Modern UI Mode, a Launch Failed message appears. (Mozilla Firefox, for example, doesn't support Modern UI mode.)
Note: You can use browsers like Internet Explorer or Chrome to launch the application in Modern UI mode.
Error occurs when you run ActionScript projects on Internet Explorer
When you run ActionScript projects on Internet Explorer, the minimum required Flash Player version is 11.4. On Windows 8, Internet Explorer comes preinstalled with Flash Player 11.3. So, when you run ActionScript projects, you see the following error:
To prevent this error, update the ActionScript compiler settings to run ActionScript projects with Flash Player 11.3, as follows:
Application content not visible in Internet Explorer Modern UI browser
When you launch an application in Internet Explorer Modern UI using the Launch Configurations dialog, sometimes the content isn't visible. Or, you see a "Get Flash Player" message in your browser window.
This issue can happen because you don't have the required version of Flash Player. Other issues while playing rich media content in the embedded Adobe Flash Player on Windows 8 also cause this issue. To troubleshoot your issue, see this TechNote.