Issue Description:

Server crash on leaving area.

What happens:

When the chunk with the altar unloads it causes a server crash.
Crash log: https://pastebin.com/8YRME5ni

What you expected to happen:

That the server did not crash.

Steps to reproduce:

1. Place altar.
2. Go far away, atleast far enough for the chunk to unload.

Or

1. Place altar.
2. Destroy altar.

Affected Versions:

• BloodMagic: 3.0.4-9
• Minecraft: 1.16.4
• Forge: 35.1.36

I seem to have had a similar issue - i placed down an altar in my creative test world, flew away (several hundred blocks, at least twice my render distance), came back, attempted to break the altar (with an altar in my hand, if that matters), and immediately got a crash-to-desktop.

https://pastebin.com/vn0LMCSZ

Using Forge 35.1.0 because i haven't updated it in a while, otherwise same versions as above.

@wrincewind Indeed, also seems happen when breaking an altar like, my friend experienced that with this very same crash: https://pastebin.com/RnikcVdc

Am I dumb? I may be dumb.

Hey look, I'm dumb. Pushing a build now to fix this, look at CurseForge in ~5m.

Thx for quick fix :-)