I have this odd issue where blocks such as furnaces, chests, and the player's inventory itself lose items stored inside them when closing Minecraft. Since this seems like it would be a rare issue, please tell me if you need extra information posted such as logs and more.
Operating System: Windows 8.1 64-bit (6.3, Build 9600) (9600.winblue_gdr.140330-1035)
Language: English (Regional Setting: English)
System Manufacturer: Hewlett-Packard
System Model: 500-054
BIOS: 80.34
Processor: AMD A8-5500 APU with Radeon™ HD Graphics (4 CPUs), ~3.2GHz
Memory: 8192MB RAM
Available OS Memory: 7366MB RAM
Page File: 3536MB used, 11252MB available
Windows Dir: C:\WINDOWS
DirectX Version: DirectX 11
DX Setup Parameters: Not found
User DPI Setting: Using System DPI
System DPI Setting: 96 DPI (100 percent)
DWM DPI Scaling: Disabled
A well known cause of this is opening the world with a 1.8 based snapshot (i.e. any snapshot in recent months) no matter how briefly. This upgrades your world to the new block id system which old versions do not understand so they don't "see" the blocks any more (at which point in time they might cause the data that they don't understand to be erased so the blocks wouldn't be visible in a snapshot anymore either)
Mods Installed
[1.7.2]bspkrsCore-universal-6.11
[1.7.2]Treecapitator-universal-2.0.3
Language: English (Regional Setting: English)
System Manufacturer: Hewlett-Packard
System Model: 500-054
BIOS: 80.34
Processor: AMD A8-5500 APU with Radeon™ HD Graphics (4 CPUs), ~3.2GHz
Memory: 8192MB RAM
Available OS Memory: 7366MB RAM
Page File: 3536MB used, 11252MB available
Windows Dir: C:\WINDOWS
DirectX Version: DirectX 11
DX Setup Parameters: Not found
User DPI Setting: Using System DPI
System DPI Setting: 96 DPI (100 percent)
DWM DPI Scaling: Disabled