I run OOO and KCAS Version 2.4.1 with the "chose three abilities when level"-option And have had no problems until now. I have Just reached 100 or more on all abilities and the next time I level I get a message that "Perfection can not be improved" (or something like that) when I click OK the same massage shows again and again. How do I brake the loop?

EDIT:
I have now uninstalled/reinstalled KCAS but it looks like the start script don't handle 100+ abilities. After the two first text screens I get the same "Perfection can not be improved"-message and no book spell. Have no clue if KCAS is running or not.
vanila game restricts attributes/abilities to 100. as mentioned below, Elys Uncapper allows attributes and abilities to be increased and effectively used up to level 200.


Oom

Use elys uncapper with Kobus. It needs OBSE to install, and you can manually set maximums for all attributes and skills up to the 255 max. It also gives bonuses for some attributes above 100, such as extra damage with melee weapons for strength.

Not 255 but 200 (as per Elys readme).