Description:

I've built place of power (ArchwayStructure), activated it, placed Necromonicon at the top, started gathering energy. After some time (about 3 minutes) Necronomicon disappears. No disruption.

Crash report:

Affected versions ("latest" is NOT a version):

• Minecraft: 1.12.2
• Forge: 1.12.2-14.23.5.2854
• AbyssalCraft: 1.12.2-.1.9.19.1

Latest log file for when the issue was present:

I have only client log (trying to get server log). It happend in 10.06 to 10.08 (there is nothing in client log - we tried again)
https://pastebin.com/5pxjbSBt

Did you place the book on a pedestal, or did you just drop it on the ground?

I dropped it to the top block.

Dropped items despawn after 5 minutes.