Sometimes even a “known good“ application, such as a sample project, does not run successfully. The problem is usually your environment.
Some demonstrations require specific setup and instructions. For example, if a sample uses web services and you are behind a firewall, you must configure the emulator’s proxy server settings or web access will fail. See Configuring the Web Browser and Proxy Settings.
If an application must run over the air (OTA), the SDK automatically installs it in the device instance.
To perform the installation, MIDlet Suites use installdir/runtimes/cldc-hi-javafx/bin/runMidlet.exe.
CDC applications use installdir/runtimes/cdc-hi/bin/cvm.exe.
Because these programs are launched remotely, virus checking software can prevent them from running. If this happens, the project compiles, but the emulator never opens. In the console you see warnings that the emulator cannot connect.
Consider configuring your antivirus software to exclude runMidlet.exe and cvm.exe from checking.
See also Troubleshooting.