Put the summary of the bug you're having here
i was working on my pvp map and i was going to test something and i did the /summon Fireball and all that happened was the fireball appeared and disappeared right away it also did the same for SmallFireball
What I expected to happen was...:
a fireball would be summoned and it would be floating in front of me

What actually happened was...:
it appeared and disappeared right awa

Steps to Reproduce:
1. Put a step by step guide on how to trigger the bug here
2. type in /summon
3. press spacebar and type Fireball then hit enter