The /summon command doesn't work on Release 1.14. Could you fix this?

Put the summary of the bug you're having here

What I expected to happen was...:

For the command to operate as normal, and summon the requested mob.

What actually happened was...:

The command didn't appear to do anything.

Steps to Reproduce:
1. Do a /summon command, using any Minecraft mob.
2. Enter the command, and it will not respond.