Display error when attempt run on command line

JavaApp/src/main/java/net/kdt/pojavlaunch/PLaunchApp.java

@@ -38,8 +38,10 @@ public class PLaunchApp {
             System.out.println("We are on java now! Starting UI...");
             UIKit.launchUI(args);
         } else {
-            // Test on cmdline
-            launchMinecraft();
+            System.err.println("UIKit could not be connected when run on command line! Please run from home screen instead. " +
+              "If you didn't see PojavLauncher on home screen, run this command:");
+            System.err.println("uicache -p /Applications/PojavLauncher.app");
+            return;
         }
 
         LauncherPreferences.loadPreferences();