Menu items not accessible

since a week I have the following problem: clicking on a menu item (i.e. home or about) results in the following error message:
Fatal error: Cannot declare class CKFormFieldList, because the name is already in use in \www\drentschepatrijs.org\www\administrator\components\com_maximenuck\elements\ckformfieldlist.php on line 0.

What is going wrong?

already thanks,
Arjan

Hi
Please check that you are up to date with Maximenu CK, and Accordeon Menu CK if you have it installed
let me know
CEd

thnx, but I have checked all the CK components and they are all up-to-date. I tried again and got the same error message
AvH

Please go in the plugins >> type maximenu >> disable them (articles, hikashop, etc...)

Yep, that did it. But does it mean that I have to disable them for good?

ok, now you can enable them again one by one, then check which one is in cause, and tell me please
if you are using the source = menu , then you don't need them now, but I need to know what causes this problem