Only Blue Square

When I run my project the only thing I get is the Default Blue Square I can move around a bit with the mouse. Everything was working fine till now. I just changed one or two values of an unimportant variable and boom - nothing works - even when I undo it. It doesnt matter which version of the project I run, it can be older versions too so I am sure its not a mistake in my programm but what the hell is going on. The programm does not care what I write even when I put an output on the top of the “public static void main(String args[])” or when I change the Display settings. Its always the same screen and I really dont know whats going on…

Sounds like you’re running the default example application. Do you have a Main class left over since creating the project, and is the project set to run Main (Project properties / Run / Main class)?
Do you run the project using F6? What if you select the class you want to run and use shift-F6 instead?

Yes it runs the Main class and with shift+F6 its not working either…

Yeah I tried it with older main classes too

OK. That is weird.
Have you made sure you’re not accidentally importing another (application) class and running it in main? It’s happened to me a couple of times when I’ve copied off an example, or other class as a template.

You having tested older versions and other projects make it unlikely, but it’s the only thing I can think of right now.

Yes it is pretty weird… Like ive said I think its a bug somewhere because the things Ive changed when it became like this they could not effect this

Well, it’s not a bug in the engine. It’s not a bug in the SDK.

Except they did.

Do a clean build.

Check your project settings to make sure it’s running the class you think.

Only other recourse is to create a new project and move the source code over.

Somehow, your project has been messed up and is including the default standard game template class. Probably you didn’t remove it. We can’t see from here so who knows?

I actually did everything you said before because I also thought that there could be a mistake. Cleaning and creating a new project and checking the properties are all things Ive done so far…

Well, you have missed something that will seem silly once you find it.

We can’t see your directory structure or any of your project settings… so you are kind of on your own until you post that.

Sounds like the IDE is running a different project/class than the one being changed. Eclipse or NetBeans?

Creating a new project won’t help if it’s running another project by default.

Right click on the actual file you’re changing and run from that menu, rather than using the toolbar run button. (Either Run As or Run File depending on IDE.)