Game crashes if more than 18 entities are in a rideable stack

Partner Rank:

2

Partner Team Reporting:

Pathway Studios

Verification builds and Platforms:

Minecraft-Release_UAP_x64_2693265 - 1.13.0.4 RC2

Summary:

Having more than 18 entities in a single rideable stack causes the game to crash.

Impact:

Limits a mechanic in an upcoming map and could cause random game crashes.

Repro Steps:

1. Download the attached world
2. Right click on the top-most sheep to add a new sheep
3. The game will crash when the player tries to add a 19th sheep

Observed Results:

The game crashes.

Expected Results:

The game does not crash.

Screenshot/Video?

Yes, attached.

Regression Builds:

Unknown.

Notes:

Only entities that the top-most entity are directly riding seem to count toward the 18 entity limit.  For example, if the bottom-most entity has 2 seats, the player can stack 16 entities on the passengers in both of the bottom-most entity's seats without the game crashing.