EV 11, error in index from search window

Hi,

EV 11 installed, when opening the search window via explorer, I browsed to a specific folder.
Right clicked a column, pressed customize - and in the property name added a wrong value.

From that moment, it cannot be edited at all, and when standing on that folder, I get an error.

meaning - I cannot remove this column at all now...

pictures attached.

also, event appears in event viewer - Invalid access to memory location. (Exception from HRESULT: 0x800703E6) (event number 41315, Index Query Server)

I guess this column property I have added is located somewhere - but how can I delete it?

Any ideas?