Issue description:
so ive tried to built some big thing but then i realised f it .. so i cancelled so i broke the builders block and i see the preview blocks are still there , i restarted the server as its our duo server with my friend its still there..

this is the picture : https://prnt.sc/ke0ci1
Steps to reproduce:

Versions:

• Minecraft: 1.12.2
• Forge: Minecraft forge : 14.23.4.2709 Forge mod loader : 8.0.99.99
• CompatLayer (only if on Minecraft 1.10 or 1.11):
• McJtyLib: 1.12-3.0.2
• RFTools: 1.12-7.54

Possibly incompatible mods and versions:

Relevant logs, if any:

If you right-click any of the preview blocks the whole preview will disappear.

Versions?

@josephcsible added