Try do a test run using only harmony & MLW (Should only take about 10 min)

If the glitch don't happen it means another mod is conflicting.

If so send me the modlist and I look into it.

I can't really fix issues that I can't recreate. So I will have to compromise.

i tried. did not work

Well then I need the modlist. Make sure you used harmony from steam and mlw from steam.

I think I was not clear. Sorry. The tier 7 troops wont work when the only mods I have active are Harmony and MLW. I did do some experimentation to give you some potentially useful insights though. You can still design a tier 7 troop, but the game calls it a tier 6. The upgrade from your tier 6 to the "tier 7", which the game calls a tier 6 as well costs 0 exp and can be done immediately. Also the tier 7 units do not have the tier 7 icon i know to exist, the crown looking symbol. Tier 7 units show up on the hideout raid screen but are not able to be selected. Whenever I have tier 7 troops in my party and sometimes while upgrading them to tier 7 the game will crash. I used cheat mode to be able to put a couple in my party. This is with only Harmony and MLW, both from steam. I think your mod is super cool, I hope i don't come across as unhappy. I enjoy it thoroughly.

Ah welll. I look into it. That sounds like a small problem in the troop xml.
I might missed the experience requirments.

Hey, I use this mod from Nexus and I had the same problem. No crash, but tier6 to tier7 upgrade was available right away, without any exp and tier7 troops had tier6 icon. Also, tier7 troops didn't have any available points in editor. After installing Tier 7 troop unlocker mod ( https://www.nexusmods.com/mountandblade2bannerlord/mods/4205 ) everything works as expected.