Put the summary of the bug you're having here

I finished a building that had item frames in it. when I returned, the item frames had de-spawned. This happened about three times in a row. Even after replacing the frames.

What I expected to happen was...:
There to be item frames when I was building in my creative world.

What actually happened was...:
When returning to the building where there were frames, they had de-spawned somehow.

Steps to Reproduce:
1. Enter creative mode in game.
2. Place item frames one with and without an item to further investigate the issue.
3. Fly away and return later.
4. Step 3 does nothing. Exit minecraft completely and re-log into world
5. Contemplate the issue.