https://gyazo.com/1a7341b37946a6c603bfac824554e765
with bob's mod
https://mods.factorio.com/mod/bobenemies

I think I know what has happened.
I will launch a fix, though really no time to load a game to test it...

What is the mod option "Highest alien tier (6)" set? Did you lower it to 4?
Restoring it to 6 or using 5 should avoid such problem.
(Guess Bob's Leviathan is recognized as tier 5. But the mentioned sprite is not loaded if this option does not catch up.)

Hello, i have set 4 (vanila)

That's right, please try setting it to 5 or 6. This should temporarily fix the problem.

The official fix will have to wait a bit.

setting 6 fix a problem, but added 2 new enemies. If you have discord can you add me ? Kubek (Khalcifer)#0277

Yes, that's why it is just a temporary fix.
I will launch a formal release (where you can set to 4 without error), maybe later of this week.

I only use Discord for voice chat in multiplayer game, but rarely load it else.
Just post here or use official Factorio forum if you want to reach me.

Should have fixed this in latest release 0.18.6 / 1.0.0.
Setting the value to 4, 5 or 6 should not matter now.
Please let me know if it works for your mod set or not.

DELETED
Strange... Double posts.

Hello, i think you fix this problem, thanks.
And i have another question, in loot table in other mod i have, there is some simple way to add a loot table. this is just an fragment loot table
["Schall-category-5-biter"] = { count_min = 1, count_max = 8, probability = 0.9 },
["Schall-category-5-spitter"] = { count_min = 1, count_max = 9, probability = 0.95 },
["Schall-category-6-biter"] = { count_min = 1, count_max = 8, probability = 0.9 },
["Schall-category-6-spitter"] = { count_min = 1, count_max = 9, probability = 0.95 }

You pasted the code, but then what is your question?
Apart from counts and probability, where is the loot item name? Fixed loot item?

Anyway, this mod does not handle any loot table.
I handle loots in my another mod Schall Alien Loot. It already contains a system of loots and ways to consume them.

Where can i send you private message?

You can PM me in Factorio forum. I usually check it in every 1-3 days.