This bug affects the following projectiles:
dragon_fireball
fireball
potion
small_fireball
wither_skull
Steps to reproduce:
Use the command /summon minecraft:fireball
Look in chat and it says "Unable to summon entity"
Look in the console/output log and it says "Tried to add entity minecraft:fireball but it was marked as removed already"
Repeat steps 1-3 with the other 4 projectiles on the list and see that it has the same result for all of them
Note: Adding coords and/or data tags to the summon command don't affect the outcome.
Thank you for your report!
However, this issue is a Duplicate of MC-86011.
You need to add the
direction
NBT tag.