Update: I switched over to a machine running Flash Builder 4 (not burrito) and it exports fine. Any one have any ideas on how I can find what is wrong so that I can report it to Adobe?
I'm getting the same problem with Burrito and Air Export using a trusted certificate.
1) Project -> Export Release Build
2) Select "Export and sign an AIR file" Click Next (the build starts)
3) In the new dialog I enter the password for the selected certificate and press Finish
4) a popup "Updating compiler settings..." a background (re)build task starts.
5) Nothing happens, the "Package Settings" dialog does not go away and I can press Finish for ever.
The problem seems to be the verbosity level of the compiler and incorrect Application Descriptor file content (which Burrito generates)
I started compiling the app using the command line (amxmlc and adt) and got various error messages.
These errors where not reported during a regular build/test inside Burrito and are introdcued with Buritto/SDK 4.5.
These where some of the issues with my project:
1) c:\PATH\TO\PROJECT\App.xml: error 303: Icon icons/appIcon_32.png is missing from package (manual addition to the App Descriptor file)
2) c:\PATH\TO\PROJECT\App.xml(11): error 105: application.initialWindow.content contains an invalid value (generated on project creation in Burrito)
3) c:\PATH\TO\PROJECT\App.xml(29): error 103: application.autoOrients is an unexpected element/attribute
4) c:\PATH\TO\PROJECT\App.xml(30): error 103: application.fullScreen is an unexpected element/attribute
5) c:\PATH\TO\PROJECT\App.xml(31): error 103: application.visible is an unexpected element/attribute
6) undefined property: var appXML:XML = NativeApplication.nativeApplication.applicationDescriptor;
Error 2: Change the line: <content>[This value will be overwritten by Flash Builder in the output app.xml]</content>
Apparently NativeApplication.nativeApplication.applicationDescriptor is not available in Hero ?
Commenting out the offending lines solved the problems, the command line build succeeded and starting the build from Burrito worked also flawlessly