good days 

i get this error:
java.lang.ClassCastException: class net.minecraft.client.player.LocalPlayer cannot be cast to class net.minecraftforge.common.extensions.IForgeServerPlayer (net.minecraft.client.player.LocalPlayer is in module [email protected] of loader 'TRANSFORMER' @3e8b3b79; net.minecraftforge.common.extensions.IForgeServerPlayer is in module [email protected] of loader 'TRANSFORMER' @3e8b3b79)
    at mercmod.blocks.classes.panel_whit_entity_inside.use(panel_whit_entity_inside.java:576) ~[main/:?] {re:classloading}
    at net.minecraft.world.level.block.state.BlockBehaviour$BlockStateBase.use(BlockBehaviour.java:826) ~[forge-1.20.4-49.0.26_mapped_official_1.20.4-recomp.jar:?] {re:classloading}
    at net.minecraft.client.multiplayer.MultiPlayerGameMode.performUseItemOn(MultiPlayerGameMode.java:324) ~[forge-1.20.4-49.0.26_mapped_official_1.20.4-recomp.jar:?] {re:classloading,pl:runtimedistcleaner:A}
    at net.minecraft.client.multiplayer.MultiPlayerGameMode.lambda$useItemOn$4(MultiPlayerGameMode.java:292) ~[forge-1.20.4-49.0.26_mapped_official_1.20.4-recomp.jar:?] {re:classloading,pl:runtimedistcleaner:A}
    at net.minecraft.client.multiplayer.MultiPlayerGameMode.startPrediction(MultiPlayerGameMode.java:251) ~[forge-1.20.4-49.0.26_mapped_official_1.20.4-recomp.jar:?] {re:classloading,pl:runtimedistcleaner:A}
    at net.minecraft.client.multiplayer.MultiPlayerGameMode.useItemOn(MultiPlayerGameMode.java:291) ~[forge-1.20.4-49.0.26_mapped_official_1.20.4-recomp.jar:?] {re:classloading,pl:runtimedistcleaner:A}
    at net.minecraft.client.Minecraft.startUseItem(Minecraft.java:1799) ~[forge-1.20.4-49.0.26_mapped_official_1.20.4-recomp.jar:?] {re:classloading,pl:accesstransformer:B,pl:runtimedistcleaner:A}
    at net.minecraft.client.Minecraft.handleKeybinds(Minecraft.java:2083) ~[forge-1.20.4-49.0.26_mapped_official_1.20.4-recomp.jar:?] {re:classloading,pl:accesstransformer:B,pl:runtimedistcleaner:A}
    at net.minecraft.client.Minecraft.tick(Minecraft.java:1902) ~[forge-1.20.4-49.0.26_mapped_official_1.20.4-recomp.jar:?] {re:classloading,pl:accesstransformer:B,pl:runtimedistcleaner:A}
    at net.minecraft.client.Minecraft.runTick(Minecraft.java:1216) ~[forge-1.20.4-49.0.26_mapped_official_1.20.4-recomp.jar:?] {re:classloading,pl:accesstransformer:B,pl:runtimedistcleaner:A}
    at net.minecraft.client.Minecraft.run(Minecraft.java:801) ~[forge-1.20.4-49.0.26_mapped_official_1.20.4-recomp.jar:?] {re:classloading,pl:accesstransformer:B,pl:runtimedistcleaner:A}
    at net.minecraft.client.main.Main.main(Main.java:234) ~[forge-1.20.4-49.0.26_mapped_official_1.20.4-recomp.jar:?] {re:classloading,pl:runtimedistcleaner:A}
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context:  im updating the briefcase from mi mod an i need to make a gui whit this image that gonna be launched from a block and from a item soo im using kapenjoe tutorials 

Spoiler

 

----------------------------------------------------------------------------------------

The problem is that tutorial is for 1.20.1 and im using 1.20.4 and i really dont get how to call and open the gui from the block nor from the item i made this based on post i made short ago
everything seems find but when right click the block to open the gui it crash the game 

	@Override
public InteractionResult use(BlockState blkstate, Level warudo, BlockPos pos, Player pe, InteractionHand hand, BlockHitResult hitresult) {

    if(warudo.isClientSide()){
        BlockEntity blkentity = warudo.getBlockEntity(pos);
        if(blkentity instanceof Panel_BlockEntity){
	            //   ↓↓↓  open the menu from the block 
            IForgeServerPlayer ifpe = (IForgeServerPlayer)pe; //<--- this is wrong  "class net.minecraft.client.player.LocalPlayer cannot be cast to class net.minecraftforge.common.extensions.IForgeServerPlayer"
            ifpe.openMenu( (Panel_BlockEntity) blkentity, pos ); //<-- i need an example of how open a gui in 1.20.4
        }
    }
return InteractionResult.sidedSuccess(warudo.isClientSide());
}
	

Theres nothing highlighted in red in the code like everything where right an possible but dont works 

#######################################################################################################

i need to see an example, just the piece of code for the use() method of the block whit the block entity for 1.20.4 
and the same  but for the item 

	   @Override
    public @NotNull InteractionResultHolder<ItemStack> use(@NotNull Level warudo, @NotNull Player pe, @NotNull InteractionHand interactionHand)
    {
        if (!warudo.isClientSide())
        {
            ItemStack heldItem = pe.getItemInHand(interactionHand);
	            
            if (heldItem.getCapability(ForgeCapabilities.ITEM_HANDLER).isPresent())
            {
	                //   ↓↓↓  open the menu from the item
                NetworkHooks.openScreen((ServerPlayer) pe, this);
            }

        }
        return super.use(warudo, pe, interactionHand);
    }
	

 

thanks for your attention 

 

 

 

 

 

9 hours ago, perromercenary00 said:

thanks for your attention 

Looks like you forgot to negate the 'warudo.isClientSide()' predicate

!warudo.isClientSide()

still not a gui not an error just a simple message

	[06:44:39] [Render thread/WARN] [minecraft/MenuScreens]: Failed to create screen for menu type: mercmod:gem_polishing_menu
	

Not a hint of what the problem is 

this silent simple error dont tell much about the problem the code i made don't show errors highlighted

 

in mi old code 1.19.4 i launch the menu part from client side 
but now i recheck the video and kapenjoe does it server side 

 

 

 

 

ya i got 
i miss the client side thing 

	// ########## ########## ##########
@SubscribeEvent
public static void onClientSetup(FMLClientSetupEvent event) {

shield_carbon_Item.make_shield_shield( ItemInit.SHIELD_CARBON.get() );
bow_item.make_bow_bow( ItemInit.BOW_CARBON.get() );
bow_item.make_bow_bow( ItemInit.CROSSBOW_CARBON.get() );
bow_item.make_bow_bow( ItemInit.CROSSBOW01_CARBON.get() );
solution_redstone_item.make_solution_shake( ItemInit.SOLUTION_REDSTONE.get() );
briefcase_blockitem.make_briefcase_briefcase( BlockInit.BRIEFCASE_BLOCK.get().asItem() );

MenuScreens.register(MenuInit.GEM_POLISHING_MENU.get(), GemPolishingStationScreen::new);
	

 

now the next part make a itemblock and open the gui from It