Hello.
I'm not sure where this is coming from, but I do have a problem with this mod.
The added tomes are not in the tomes library. Even with a new game, these tomes are not available. And they don't appear in the full list of tomes.
Just in case, other mods like the extended cultural units work perfectly. So it shouldn't be the bug causing problems installing mods.

Hi mate, are you using any other Tome Mods? It’s likely an incompatibility.

Sadly, it's not the case. I only use the mod that allow multiple tier 5 tomes.
I charged a playset without it and it still not work.

Can you post a full mod list here?

Of course.
Here are the mods I used:
-Age of colors
-Multiple Guilds
-Level Cap 30
-Neverr's Mods - Expanded hero traits
-Optional Cosmetic Transformations
-Expanded Cultural Units
-Unlocked Factions
-RFD
-RazeRuins
-Alt Alt Wightborn (Clean Heroes)
-Wondrous Item Pack
-Tomes of Valor and Victory

I can't really see which of these mods could be causing the problem.
Anyway, thanks again for taking the time to look at this.

The new Lizardmen race Huscarls are missing their helmets.

@BahamuT, that’s not a bug, Lizardmen of most cultures do not wear helmets.

I'm leaving this here if you get back to updating this mod at some point. Huscarl units appear to be missing their weapon if you are playing as a Reaver culture faction.

Additionally, the Huscarl is missing a transport boat model when it goes into the water.

Looks like the AI is building Proving Grounds in coastal terrain... working as intended?