well, I've re-installed whole game, and my old party was still there.when I click on some spells.
It's blank and wasn't showing anything. spell worked normally, but how is it supposed to happen?
Example:Holy Smite
go to priest spell→go to 3rd lv→right-click Hs:
and it says:


so How am I supposed to fix it?

Which mods do you have installed?

no mods. but I've installed SPItemcollection(uninstalled) and Cleric Remix(From Glibberlings 3, still installed)

Is the save from your earlier game? The one with the mods which you have now uninstalled. There could be a problem with that then.

You installed a mod, ToB or the official patch with the game or a game editor running. You need to reinstall your game.

sth like that happened to me once. in my case kit descriptions were gone. i re-installed SPCollection and it was solved.

I guess when you uninstall the game you should've deleted whole BG2 folder, then re-install the BG2.

After I installed TDD and uninstalled it, I couldn't even start the game. However after replacing whole files of BG2 from my new computer, it's working fine.

or your old save just don't work with no mod game which I doubt.