Crash when throwing item into portal.

What version of Linking Books are you using? 0.2.1.0

What version of Forge are you using? 35.1.36

What version of Minecraft are you using? 1.16.4

What modpack and modpack version are you using, if any? custom

Does the bug occur server-side, client-side, or both? Single Player

Paste a link to your log or crash report here. Use a service like pastebin. No images, please. crash-2021-02-12_11.27.51-server.txt

Describe the bug Game crashes when items are thrown into linking book portal.

To Reproduce

1. Grab blank linking book from Creative Menu and right click.
2. Go to another dimension (Nether and Overworld and vice versa was tested).
3. Add linking book to portal frame.
4. Throw item in portal.

Expected behavior I'll admit not using the portal as intended but was assuming the item would appear at linked location.

Additional context When crashing while in the Overworld and the re-entering the world, I'm located near spawn instead of near the portal in question. When trying this in the Nether, I was located inside wall of netherrack about 600 from spawn(Also next to a lava source but was in creative). I tried created link on the ground and mid-air with same result. Was able to throw item through nether portals.