crash-2020-04-26_12.37.59-client.txt

The author of Creative Core and Little Tiles said that they would have a fix out for this sometime. Once that fix comes out, this issue will be closed.

CreativeMD just yesterday made some releases of CreativeCore and LittleTiles with a fix for this crash. We intend to include these updates in 1.2.3 so this might be resolved by that.

It seems the crash is actually related to LittleTiles (or rather CreativeCore, its dependency):

java.lang.ClassCastException: net.minecraft.client.entity.EntityPlayerSP cannot be cast to net.minecraft.entity.player.EntityPlayerMP
	at com.creativemd.creativecore.common.utils.mc.PlayerUtils.getGameType(PlayerUtils.java:31)
	at com.creativemd.littletiles.common.action.LittleAction.canPlace(LittleAction.java:322)
	at com.creativemd.littletiles.client.render.overlay.PreviewRenderer.drawHighlight(PreviewRenderer.java:244)
[...]

I feel like I've seen this one before. I'll see if I can pull up how we resolved it for the last person with the issue.

I have reported this issue to the author of CreativeCore and LittleTiles. If you are not currently relying on LittleTiles for its custom blocks, perhaps disabling both of these in your launcher would work as a temporary workaround.