Doesn't work

[hfcipriano]

Hi! When i run the app on Intellij to build the plugin, another instance of intellij is opened.

[javatlacati]

That is not just "another instance" is the "development instance" a sandbox that prevents you to install your code in your current IDE and crash it forever. You just have to import your jar file from the plugins section of your settings once you are positive that it works and will not harm your IDE.