To restate:
Art School = Teens
Music School = Children
(even though they take place on the same lot)

School of Peace and Love = Generations. The Boarding Schools have nothing to do with the community theater, if you enroll your child or teen in one of those then a limo comes the next day to take them out of your world where the school is. This isn't related to the Careers mod schools.

I think the only thing left we have to wonder about is if maybe the Polish translation of the mod got updated, something went wrong, and that's what's preventing all of the options from appearing where they should now when they did for the OP before.

@gwiazdochron - Your mod versions as reported on that Overwatch screenshot from before are fine.

The translation looks fine to me.

<KEY>Gameplay/Excel/Careers/CareerList:ArtsSchool</KEY>
<STR>Liceum Humanistyczne</STR>
<KEY>Gameplay/Careers/GetJobInRabbitHole:JoinCareer6462623313726928547</KEY>
<STR>Zapisz się do Liceum Humanistycznego</STR>

<KEY>Gameplay/Excel/Careers/CareerList:NRaasChildMusicSchool</KEY>
<STR>Szkoła Muzyczna</STR>
<KEY>Gameplay/Careers/GetJobInRabbitHole:JoinCareer11476477153280014677</KEY>
<STR>Dołącz do Szkoły Muzycznej</STR>

Unfortunately I don't have any other suggestions. It looks like we've covered everything and there's no reason they shouldn't show up. Installing Generations making art school show up sounds equally odd because Generations is not a requirement of it. At this point it sounds like your game is throwing random variables.

How was your base game and the other expansions acquired?

Hi guys!
So I found my sims3 backup folder - one, who had Nraas Mods istalled while i had Polish version of my Windows System. There for Nrass i installed in game had automatic polish language. And game i was playing back then was in default polish. After that, I uninstalled the game and backup my folder in my storage disk. Now i have an english system and downloaded the game when when downloaded I had to chose polish language. Then I installed everything from zero - also downloaded Nraas mods again - and when I restored saved games from backup folder - Careers didn't work properly. And they dont - as you see in my earlier post - even I cleansed everything and make game create new folder of Sims3 in Documents. So far the error remains.

So I came back to my backup folder and replaced my new Nraas mods (with bugged Careers with no working art schools and no additional activities during school time) with my OLD ones I have installed when i had polish system back then. And guess what. Its working. So like I said. Somethings wrong with language stuff.
I am very happy that i had this backup !
old nraas downloaded in pl system, working now screenshots :
https://i.imgur.com/FgoE1CI.jpg - choosing school by master controller
<a class="wiki_link_ext" href="https://i.imgur.com/hLPVJaE.jpg" rel="nofollow">https://i.imgur.com/hLPVJaE.jpg</a> - activities during schooltime

But problem still remains with computer- there is no Art School to choose by computer... again
<a class="wiki_link_ext" href="https://i.imgur.com/Udg57DT.jpg" rel="nofollow">https://i.imgur.com/Udg57DT.jpg</a>