I was creating a container, and, to do this, I looked the DispenserContainer to understand the methods. So I created the container and added the slots(of container and player inventory). But, when I open the container, the item in the container slots or in the player inventory slots duplicate, and one of them its in my cursor(the image explain better). I'd like to know if its a bug or an error in the code writing. Thanks.
I think I've found the cause of the problem. A recently updated Java installation installed just the JRE instead of the JDK, and was causing gradle to be unable to find tools.jar. Installing the updated version of the JDK seems to have fixed the problem. Thank you, and I apologize for wasting your time.