Simulink External mode crashes while running on TI F28379D Launchpad

I am using a TI F28379D Launchpad as a motor controller. I will run my controller model in external mode on the launchpad, and it will upload and start to run. Often, the model will randomly crash while in external mode and will stop communicating with the Launchpad. I will get the following error:

External Mode Open Protocol CheckData command failed

Caused by:

• Multiple errors detected.
• XCP serial port error: serial port send error
• Error detected while trying to disconnect Simulink from target application.
• Could not disconnect from target application: XCP serial port error: serial port send error

What does this mean? How do I fix it?