Hello.

I don't know if I am a single person in the universe with this issue, as I scoured the internet several times, but found no solution. It's a thing that practically makes it impossible for me to enjoy Morrowind. Everytime I go into spellmaking or enchanting menu, it allows me to click OK/ Cancel button only in case when spell effect is "On self". If I try "On touch" and "On target" the menu box is somehow "incomplete on the downside" and allows no exit, scrolling down doesn't work either. The problem appeared somewhere during my gameplay, not exactly sure when, but in the beginning everything worked OK. So, is the only solution complete reinstall ? Thank for all kinds of help.

There are several overhaul mods that restrict enchanting options. Have you installed one of those?

Another possibility is you have increased font size. The on target and on touch menus may be larger than on self and not fit with the dialog box. I used to have this problem when using larger fonts, which is why I use MGE XE UI scaling instead to make the font more readable without blowing out the dialog boxes.