Problem/Bug ThrownPotion entity XXXX has no item?!

My server console is getting SPAMMED with this message over and over. However unlike the old threads that I found also discussing this issue, I know exactly what is causing it. Unfortunately, I don't know how to fix the messages from showing up.

Basically I have some custom spawners that are spawning in splash potions of jump boost, and whenever they run it spams the console. Here is the exact command that I used to make the spawners:

Code:

setblock ~ ~ ~ minecraft:spawner{SpawnCount:3,SpawnRange:2,Delay:0,MinSpawnDelay:5,MaxSpawnDelay:5,MaxNearbyEntities:5,RequiredPlayerRange:2,SpawnData:{id:"minecraft:potion",Potion:{id:"minecraft:splash_potion",Count:1b,tag:{CustomPotionEffects:[{Id:8b,Amplifier:5b,Duration:40,ShowParticles:0b}]}}}} replace

Is there any way to prevent these spawners from sending out the console error messages every time someone gets close enough to trigger them to run?

Here's what the errors actually look like: http://prntscr.com/nx8y86