Player863

Advanced OpenGL (set to fast in my case) was definitely causing the issue. Turning it off fixed the crash. Thanks for the help!

I am running Optifine, yes: version HD_U_D5. A quick test without it does not give me the "Already Tessellating" error - the world loads fine without it. My Java is 64-bit. As far as I can tell, every last block remains the same after the error is thrown. My first thought was that it was a concrete conflict between OptiFine and DimDoors, but after starting up a Superflat world, placing a DimDoor, entering it, and exiting it, everything loaded fine. There's definitely a third culprit here, but I can't tell what.

Title: Already Tessellating Error Version: 1_0_4 OS: Windows 7 Java Version: Version 7, Update 25 (build 1.7.0_25-b17) Description of Problem: After I leave my pocket dimension (courtesy of Dimensional Doors), I'm confronted with the error posted below. Exiting a Nether Portal or loading the world from the Main Menu do not provide the same response. I can provide a world save if needed. Note(s): - A noteworthy occurrence: after entering the overworld from the DimDoor but before it throws the error at me, entities render (such as creepers and endermen) and the player renders, but the world itself does not. - May be relevant (from the error log): OpenGL: Intel® HD Graphics GL version 2.1.0 - Build 8.15.10.2189, Intel PLEASE READ: - My Hexxit version as stated in the Technic Launcher is ACTUALLY 1.0.5, but that's not a selectable option for some reason. Perhaps I'm misinformed? Error Messages: Error Log: java.lang.IllegalStateException: Already tesselating! at net.minecraft.client.renderer.Tessellator.func_78371_b(Tessellator.java:481) at net.minecraft.client.renderer.Tessellator.func_78382_b(Tessellator.java:471) at net.minecraft.client.renderer.ItemRenderer.func_78439_a(ItemRenderer.java:173) at net.minecraft.client.renderer.ItemRenderer.renderItem(ItemRenderer.java:129) at net.minecraft.client.renderer.ItemRenderer.func_78440_a(ItemRenderer.java:505) at net.minecraft.client.renderer.EntityRenderer.func_78476_b(EntityRenderer.java:769) at net.minecraft.client.renderer.EntityRenderer.func_78471_a(EntityRenderer.java:1738) at net.minecraft.client.renderer.EntityRenderer.func_78480_b(EntityRenderer.java:1122) at net.minecraft.client.Minecraft.func_71411_J(Minecraft.java:871) at net.minecraft.client.Minecraft.run(Minecraft.java:760) at java.lang.Thread.run(Unknown Source)