Question

I can run my software without any problems in my IDE, but when I try to compile it to a jar, and try to run it, it says that the main class can’t be found. I succeeded to make it work perfectly several times in the past, but I found this problem few time ago, so I can’t really know when it went wrong.
The jar has a META-INF, all properly set up, like in my older versions, and the main class is there. Other peoples can’t compile too, so it’s not just me. The code is on Github, so that could be a tool to help me solve this.

But I want to know, just by reading this, is there some common mistakes that could cause this, or this is uncommon?

EDIT:
I’m using IntelliJ IDEA
and I will check if the versions are the same.

EDIT2:
They do have the same version, and it’s exporting an executable jar with the correct main class defined, as I have beeing doing for all the previous versions.

Answer 1

Check that the MANIFEST.MF is present in the META-INF folder of the jar, and make sure that the line :

Main-Class: yourMainClass

is present inside the file, then make sure that you start the jar with this command line :

java -jar yourjar.jar

Have you tried to launch the jar file specifying the main class ? For example :

java yourjar.jar yourMainClass

Does it work in this way ?