Error invoking method, failed to launch jvm

I ran into the same problem; the following worked for me and helped me make sense of those blasted “Error invoking method.” and “Failed to launch JVM” dialogs:

1. Find your .jar file
   • It has the same name as your Project and it’s in your application’s installation directory under AppData\Local\{ApplicationTitle}\app (shortcut: type %appdata% into explorer); if your project was named HelloWorld, there you will find HelloWorld.jar
2. Navigate to it’s directory in command prompt
   • shift+Right Click any blank spot in the Explorer window and choose “Open command window here” (that’s a fancy trick I recently learned; alternatively you would cd to the same directory using the command prompt)
3. Run your .jar via the command line
   • type java -jar "HelloWorld.jar" and hit Enter

Tadah! Behold your hidden exceptions (the existence of which “Error invoking method.” so vaguely tries to communicate to you). *

If your problem is similar to mine it stems from a file structure difference between the project out folder and the installation directory, and that’s why the program compiles just fine in the editor and builds just fine—there isn’t a problem until it’s built out, and the file structure is a little different.

*If you didn’t get anything when you ran it via the command line, look for any errors that could be happening during that initialize() method; that’s where your problem likely is. You can expose any exceptions during runtime by using a Popup Exception Dialog like shown in a similar problem, here.