Invalid menu handle
If a strange error “Invalid menu handle” appears to you in IntelliJ IDEA when you are trying to run an application, it means the path of your default application executor is broken. For example, you need to reinstall the flash player if you run swf files.
No JDK specified in Ant
This error message can be displayed when you are trying to run ANT build. It is caused when your default Project SDK is set to non-Java SDK (Flex SDK whatever). So just open Project settings window and select any JDK in Project->Project SDK combobox.