Put the summary of the bug you're having here
What I expected to happen was...:
Nothing, everything should have stayed the same.
What actually happened was...:
I was in the end and when I relog into the world I would be back where I was a few minutes ago, and I went back into 1.7.4 to fix it and when I got back on all my items, in my inventory, chests, and ender chests were gone.
Steps to Reproduce:
1.Quit minecraft
2.reopen in the snapshot.
3. and look in your inventory and chests.
Related issues
duplicates
Comments
migrated
Downgrading versions is NOT supported, thus why changing the launcher to snapshot / development versions says to use a different folder and backups. This is known and not unique to these snapshots, inventory, chests, and item frames lose their contents, but given that backwards compatibility is not guaranteed this isn't a bug.
EDIT: See MC-45009