Assert error for Jungle Zoo in 1.13 dev build

Summary: Assert error appears in 1.13 dev build when going to a certain location in Jungle Zoo.

Verification builds: Minecraft.Windows_1.13.4.0_x64_UAP.Release

Impact: Assert error appears in 1.13 dev build when going to the crocodile enclosure. (See attached image for more info about the error.)

Repro Steps:

1. Make sure you're using 1.13 dev build.
2. Load Jungle Zoo with the world template.
3. Go in creative mode.
4. Fly to the crocodile enclosure.
5. See attached video for an example.

Observed Results:

Assert error appears.

Expected Results: No assert error should appear.

Screenshots/Videos attached: Yes