JavaFX Error occured during initializing of boot layer (IntelliJ)

Question

i am using javafx for the first time and i get an error when i run a simple program :

Error occurred during initialization of boot layer

java.lang.module.FindException: Hash of javafx.base (29158284a7e9fd7c1303a1b262a5541913ebab69892ff25cf59db511cd7a6eca) differs to expected hash (fffde8f0d0c19d6a82793cd0bef8c93e0a518106b36a82844c60228bf7a134ee) recorded in java.base

I have watched many youtube tutorials but none of them show the error that i get. I also created a module-info.java :

    module javafx {
        requires javafx.fxml;
        requires javafx.controls;
        opens sample;
    }

I am using the 11.0.4 java version and i recently downloaded javafx 15.

If anyone knows the solution to this problem would be very helpful :)